Combination products of tobramycin compounds and dexameihasone compounds

ABSTRACT

Disclosed herein are new compositions comprising (1) an antibacterial component comprising (a) a complex comprising (i) an active pharmaceutical ingredient (API) wherein the active pharmaceutical ingredient is tobramycin, a similar compound, or a derivative of either thereof and (ii) a complexing agent, or (b) a derivative of tobramycin or a similar compound comprising one or more conjugates/derivatizing groups, wherein the complexing agent or conjugate(s) cause a detectable increase in API permeation of corneal cells, retention in corneal cells, or both, as compared to the non-complexed or non-derivatized API, and (2) an effective amount of an anti-inflammatory agent, such as dexamethasone or another dexamethasone compound. This disclosure also describes new methods of using such compositions, producing such compositions, and the like.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application claims priority to U.S. Provisional PatentApplication No. 63/029,313 filed May 22, 2020, entitled “TobramycinCompound Compositions for Ophthalmic Delivery and Associated Methods ofProduction and Use.” This application claims the benefit of priority to,and incorporates by reference the entirety of, this above-referencedpriority application.

FIELD OF THE INVENTION

This invention relates to new ophthalmological compositions, processesof preparing such compositions, and new methods of treating conditionsof the eye, as well as other additional aspects and features describedfurther herein.

BACKGROUND OF THE INVENTION

A high value is placed on vision and eye health. As such, considerabletime and resources are spent on ophthalmic product development. Suchproducts can be divided into two categories by the location within theeye they aim to target: the anterior and posterior segments. Theanterior portion comprises about one-third of the eye and consists ofanatomy including the conjunctiva, cornea. The posterior portioncomprises anatomy all residing behind the lens. Products targetingdiffering portions of the eye require different considerations, as thechallenges presented by the biological environments, barriers, andnatural ocular defenses vary between the two.

Common broadly categorized disorders of the anterior portion of the eyeinclude cataracts, infection, and inflammation, inflammation sometimesresulting from infection and other times present independent frominfection, resulting from other etiologies such as allergy. Suchafflictions, especially infection and inflammation, can vary and canaffect humans of all ages (e.g., from infants to the very young and theelderly) as well as other species. The efficacy of topical applicationssuch as those attempting to treat eye conditions such as conjunctivitis(inflammation of the conjunctiva), or other external ocular infectionsoften hinge on their ability to maintain contact with the afflicted eyeanatomy or be retained by the eye, e.g., permeate and be held within,the cornea.

Tobramycin is an aminoglycoside that has been used in ophthalmologicaland other settings as an antibiotic. Several other aminoglycosides areknown, and several such antibiotics have been shown to be useful inophthalmological treatments. However, aminoglycosides can varysignificantly in terms of their structure, effectiveness in differentsettings, and other attributes. Tobramycin, for example, is unique amongmajor aminoglycoside antibiotics in binding the 50 s ribosome inaddition to the 30 s ribosome typically only bound by otheraminoglycosides.

Not long after the patenting of tobramycin in the mid-1960s and thereceipt of approval of tobramycin for medical use in 1974, Novartis, aleading global pharmaceutical company ranked as one of the top fiveglobal pharmaceutical innovators, developed the first ophthalmologicaltobramycin product, TOBREX®, receiving FDA approval for the product inlate 1980. The specific approved indication for TOBREX® is the treatmentof external infections of the eye and its adnexa by susceptiblebacteria. TOBREX® tobramycin ophthalmic solution provides tobramycin ina 0.3% w/v concentration. Due to the many sensitivities of the eye, forexample relating to pH and tonicity, concerns related to irritation madedelivering higher concentrations of tobramycin challenging and productshaving higher concentrations of tobramycin have not been approved todate. Due to the limited concentration, as well as tobramycin's lowcorneal permeability and hence limited ability to be effectively takenup by corneal cells (e.g., before being swept away by natural eyedefense mechanisms such as nasolacrimal flushing), frequent, repeateddosing of the product is required. In fact, recommended dosing ofTOBREX® in adults and children above the age of one year is theapplication of one-two drops into the affected eye(s) every four hours(at least six times a day). In severe infections, recommended dosing ofTOBREX® in adults and children above the age of one year is theapplication of two drops into the affected eye(s) hourly.

The introduction of TOBRADEX® by Novartis followed in 1988. TOBRADEX®further incorporates the steroid dexamethasone with tobramycin in aneffort to address the inflammation commonly associated with ocularinfections and use of products such as TOBREX®. Unfortunately, theintroduction of the steroid to the formulation also introduced newconcerns, specifically an increased risk of increased intraocularpressure and glaucoma, with associated risk of damage to the optic nerveand defects in visual acuity and fields of vision. Further warningsrelated to cataract development, delayed post-surgical healing,secondary infection due to suppressed host response, exacerbation ofviral infections, development of fungal infection, and use by pregnantand nursing women as they relate to fetal anomalies and mortality areprovided on the TOBRADEX® label. At the same time as introducing newsafety concerns, the concentration of tobramycin remained the same at0.3% w/v. As such, the dosing regimen remained essentially unchanged,with administration prescribed as one drop administered every 4-6 hours,optionally the initial 24-48-hour dosing being increased to one dropevery 2 hours.

It took nearly another 20 years before another product comprisingtobramycin was introduced into the market. Specifically, in 2004, Bausch& Lomb launched a product like TOBRADEX® called Zylet®, a formulation oftobramycin at a concentration of 0.3% and a steroid, in this case thecorticosteroid loteprednol etabonate, at a concentration of 0.5%.

Over the course of the following decade and a half, many more attemptswere made by formulators to develop tobramycin products and otherophthalmic interventions utilizing a variety of technologies to addressthe well-known drug availability and/or bioavailability limitations,e.g., drug permeability and retention limitations, and intervention sideeffect vulnerabilities presented by the eye.

For example, an attempt to develop a twice-a-day tobramycin formulationreportedly used viscosity enhancers, as exemplified in the 2005 EuropeanJournal of Ophthalmology paper by Kernt et. al. titled, “A ClinicalComparison of Two Formulations of Tobramycin 0.3% Eyedrops in theTreatment of Acute Bacterial Conjunctivitis.” This work reflectedresults from a large, multi-center clinical trial. However, despite suchsignificant use of resources, this study and other, similar efforts ledto no new marketed product. While the fate of such efforts is difficultto ascertain from public records, given the effort and the outcome, suchfacts suggest that such product candidates may have been associated withan issue or shortcoming in terms of product efficacy, safety, or both.

In 2009, a modified TOBRADEX® formulation, TOBRADEX ST®, was introduced.TOBRADEX ST® comprises tobramycin at the previously marketedconcentration of 0.3% w/v (as present in both TOBREX® and TOBRADEX®) andmaintains the presence of the steroid dexamethasone (as in TOBRADEX®);however, the formulation is modified such that the concentration ofdexamethasone is decreased from 0.1% in TOBRADEX® to 0.05% in TOBRADEXST®. While reducing the steroid exposure and hence attempting to addressthe risks associated with such steroid use, the concentration of theantimicrobial tobramycin in the new formulation remained unchanged ascompared to earlier products, with dosing remaining at a regimen of 1drop every 4-6 hours and optionally a drop every 2 hours during theinitial 24-48-hour treatment period.

Despite significant investigation in these and a multitude offormulation approaches reported in the art, and the proposed developmentof tobramycin derivatives with allegedly improved properties reportedseveral times in patent documents and scientific literature, notobramycin or tobramycin derivative product addressing the limitationsassociated with on-market tobramycin products, such as dosing and dosageamount, has yet materialized. As a result, earlier developedformulations continue to dominate the market and the most significantrecent introductions are primarily targeted at reducing the side effectsassociated with such formulations. In fact, in the nearly forty yearssince the approval of TOBREX®, no approved product has adequatelyaddressed the limitations associated with tobramycin products. Thedisappointing progress of tobramycin product research and developmentdemonstrates that inventiveness is required to make tobramycin productsthat can effectively address the limitations associated with currenton-market products.

Perhaps one factor complicating such research efforts is the numerousoptions available for seeking to develop improved ophthalmologicalproducts. For example, mucoadhesive formulations, ocular/conjunctivalinserts, the use of aqueous gels, dendrimers, liposomes, andnanotechnology, among others have been used for developingophthalmological products. These approaches have been combined withnumerous types of formulations including solutions, emulsions,suspensions, ointments, and the like. Means of addressing drug transportvia, e.g., solute carriers and ATP-binding cassettes have beenintroduced; use of prodrugs, iontophoresis, and cyclodextrins have eachbeen subjects of research and development efforts. These and numerousother approaches available to the development of such products aredescribed in, e.g., Souto, in “Advanced Formulation Approaches forOcular Drug Delivery: State-Of-The-Art and Recent Patents,” published inPharmaceutics in 2019 which provides a review of the numerous techniquesavailable for developing ocular formulations. The number of availableoptions, and the complexities of making suitable products for treatingconditions of the eye given its sensitive and unique physiologicalnature, further reflects that an inventive approach is required todevelop a tobramycin composition addressing limitations of currentlymarketed tobramycin ophthalmological products which have reflected thestate of the art for four decades.

SUMMARY

Certain aspects of the invention described in this Summary refer toaspects described in other paragraphs, incorporating all of the elementsof any such one or more referenced paragraphs. To facilitate suchreferencing, a paragraph number is provided at the end of each paragraphin this section.

The invention described here provides new pharmaceutical compositionscomprising a combination of (a) a compound that is either (i) a complexformed between (A) an active pharmaceutical ingredient that is eithertobramycin or a tobramycin-like compound (e.g., an analog, derivative,or alternative form of tobramycin) and (B) an ophthalmologicallysuitable lipophilic and amphoteric complexing agent, wherein thecomplexing agent promotes the uptake of the composition by cornealcells, the retention of the complex by corneal cells or both as comparedto the free compound, or (ii) a derivative of tobramycin having similarcorneal cell uptake properties to such a conjugate, similar corneal cellretention properties to such a conjugate, or both a similar corneal celluptake and retention properties to such a conjugate and (b) an effectiveamount of dexamethasone or another dexamethasone compound (e.g., ananalog or alternative form of dexamethasone or a derivative of any suchanalog, alternative form, or dexamethasone) (Summary paragraph 2).

The compositions provided herein address a failure of the current art toprovide an effective therapeutic antimicrobial treatment for infectionsof the eye, wherein the active contained therein is successfully able topermeate the cornea, be retained by the cornea sufficiently to allow fora reduced dosing schedule, or both, and the presence of one or moreadditional active agents in compositions comprising compounds orcomplexed compounds described provides further treatment of either theprimary indication of the composition, such as microbial infection ofthe eye or its adnexa, or to related indications such as, for example,inflammation which can accompany such a primary indication. Through themodification of tobramycin (developing derivatives thereof and/orcomplexing tobramycin or a tobramycin derivative with a complexingagent) and by supplying tobramycin or tobramycin derivative (the primaryactive) and at least one additional active agent such as dexamethasoneor a dexamethasone compound in a composition or formulation havingcertain properties, a product can be obtained having the ability oftobramycin to be taken up by and delivered across the cornea morerapidly than tobramycin in conventional formulations and/or, further, tofacilitate the formation of a depot of the primary active within thecornea for extended release, reduced dosing frequencies and theresulting benefits of the same can be achieved. The invention describedherein is presented to address a failure of the current art to providean effective therapeutic antimicrobial treatment for infections of theeye, wherein the active contained therein is successfully able topermeate the cornea and be retained by the cornea sufficiently to allowfor a reduced dosing schedule. In embodiments, the invention describedherein in comprising an anti-inflammatory agent such as dexamethasone ora dexamethasone compound is further capable of alleviating one or moreadditional indications, such as a secondary indication related to amicrobial infection, e.g., a detectable or significant reduction ofinflammation accompanying an ocular infection (Summary paragraph 3).

The modification of 4,6-disubstituted deoxystreptamine structures, suchas in some aspects creating specific derivatives of tobramycin,combining such structures with one or more delivery agents, or both, canresult in the ability of the resulting composition to permeate and beretained by the cornea more successfully (rapidly and longer,respectively) than tobramycin in conventional formulations, such as inTOBREX®, and/or, further, to facilitate the formation of a depot of theactive within the cornea. Such physiological differences in thecompositions of the invention can, in some aspects, result in differentpharmacological conditions of such, such as, e.g., extended release,reduced dosing frequencies, and other benefits described herein (Summaryparagraph 4).

According to certain aspects, the invention provides compositionscomprising a pharmaceutical composition comprising an antimicrobialactive pharmaceutical ingredient comprising an effective amount of acompound having a structure according to the formula

wherein (1) R¹ is —CH—NH₂ (i.e., methyl-NH₂ or Me—NH₂) or an optionallysubstituted alkyl, an optionally substituted aryl, an optionallysubstituted aralkyl, an optionally substituted cycloalkyl, an optionallysubstituted cycloalkylalkyl, an optionally substituted heterocyclyl, anoptionally substituted heterocyclylalkyl, an optionally substitutedheteroaryl, or an optionally substituted heteroarylalkyl; (2) R⁴, R⁶,R⁸, and R⁹ are —NH₂ or an optionally substituted alkyl, an optionallysubstituted aryl, an optionally substituted aralkyl, an optionallysubstituted cycloalkyl, an optionally substituted cycloalkylalkyl, anoptionally substituted heterocyclyl, an optionally substitutedheterocyclylalkyl, an optionally substituted heteroaryl, or anoptionally substituted heteroarylalkyl; (3) R² is —Me—OH or anoptionally substituted alkyl, an optionally substituted aryl, anoptionally substituted aralkyl, an optionally substituted cycloalkyl, anoptionally substituted cycloalkylalkyl, an optionally substitutedheterocyclyl, an optionally substituted heterocyclylalkyl, an optionallysubstituted heteroaryl, or an optionally substituted heteroarylalkyl;and (4) R³, R⁵, R⁷ and R¹⁰ are —OH or an optionally substituted aryl, anoptionally substituted aralkyl, an optionally substituted cycloalkyl, anoptionally substituted cycloalkylalkyl, an optionally substitutedheterocyclyl, an optionally substituted heterocyclylalkyl, an optionallysubstituted heteroaryl, or an optionally substituted heteroarylalkyl(Formula I), optionally complexed with a lipophilic and amphotericcomplexing agent, wherein the composition further comprises one or moreadditional active agents which target(s) the primary indication or arelated indication, and further wherein the composition isophthalmologically safe and the complexing agent, when present,detectably promotes the uptake of the composition by corneal cells, theretention of the complex by corneal cells, or both, as compared to thefree compound. In one aspect, the group of such compounds can includetobramycin. In one aspect, such a group of compounds excludestobramycin. In one aspect, the one or more additional active agents isan anti-inflammatory agent. In one aspect, the one or more additionalactive agents is dexamethasone or a dexamethasone compound (Summaryparagraph 5).

In aspects, no more than three of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹,and R¹⁰ of Formula I differ in composition from the correspondingposition in tobramycin, such as no more than two or no more than one ofR¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, and R¹⁰ differ in composition fromthe corresponding position in tobramycin (Summary paragraph 6).

In certain aspects, the pharmaceutical composition complexed with theabove-described complexing agent more specifically comprises anophthalmologically suitable antibiotic compound that has a structureaccording to the formula:

wherein R¹-R⁸ have the characteristics of the following paragraph(Formula II) (Summary paragraph 7).

In certain aspects, the invention provides such a composition wherein nomore than three of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, and R⁸ differ from thecorresponding position in tobramycin, such as no more than two or nomore than one of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, and R⁸ differ from thecorresponding position in tobramycin. In certain further aspects, R²,R⁷, or both are the same as the corresponding positions in tobramycin.Still further, in some facets R² is a —Me—Oh and R⁷ is an —OH (i.e.,these positions have the same composition as the corresponding positionsin tobramycin) (Summary paragraph 8).

In certain aspects, a compound of Formula II has a structure accordingto the formula:

wherein R groups are described in the following paragraph (Formula III).In certain aspects, the compound of Formula III is tobramycin (Summaryparagraph 9).

In some facets, the invention provides a pharmaceutical compositiondescribed in Summary paragraphs 2-9, wherein any R group that differsfrom tobramycin includes an optionally derivatized 2-20 atom backbonealkyl or heteroalkyl group (an alkyl group comprising one or moreintervening heteroatoms), optionally attached through an ester or amidebond at a position corresponding to an —OH or —NH₂ group in tobramycin.In certain facets, the alkyl or heteroalkyl group primarily comprises,generally consists of, or consists of a linear alkyl or heteroalkylcompound (comprising a linear backbone and typically comprising sidechains of only 1-4, 1-3, 1-2, or only a single atom/group, e.g., —NH₂ or═O). In some aspects, the group is or generally consists of a fattyacid, fatty acid derivative, short fatty acid, or short fatty acidderivative. In certain further aspects, the group is or generallyconsists of an acetic acid or palmitic acid group (skilled readers willunderstand that such groups may be modified from their original chemicalcomposition in order to facilitate bonding to the backbone, e.g.,through the formation of an amide bond, ester bond, or the like). Incertain aspects where the alkyl or heteroalkyl group is a linear alkylor heteroalkyl compound, the alkyl or heteroalkyl group comprises one ormore —C═O or —NH₂ groups bound to the backbone. In some facets, thegroup comprises at least one —C═O group and at least one —NH₂ groupbound to the backbone. In some alternative aspects where the alkyl orheteroalkyl group is a linear alkyl or heteroalkyl compound, the groupcomprises no —C═O groups. In certain aspects wherein where the alkyl orheteroalkyl group is a linear alkyl or heteroalkyl compound and thegroup may or may not comprise at least on —C═O group, the group cancomprise at least two —NH₂ groups bound to the backbone. As noted, abackbone AOA can comprise such groups or other heteroatom groups as partof the backbone itself (Summary paragraph 10).

In some aspects, the invention provides a composition described inSummary paragraph 10, wherein the backbone of the group is a heteroalkylstructure comprising at least one nitrogen, at least one thiol/sulfur,or both. In certain further aspects, the invention provides any suchmolecule wherein at least about 90% of the atoms of the backbone arecarbons. In further aspects, the backbone comprises or is bound to anoptionally derivatized 3-9-membered cycloalkyl or heterocycloalkyl ring.In certain facets, the backbone comprises or is bound to a 3-6 memberedring wherein the ring comprises one or more nitro groups, is bound toone or more nitro groups, or is bound to one or more side chains boundto one or more nitro groups. In some compositions wherein the backbonecomprises, or is directly or indirectly bound to, an optionallyderivatized 3- to 9-membered cycloalkyl, heterocycloalkyl, aromatic, orheteroaryl/heteroaromatic ring, or a 3-6 membered heterocycloalkyl orheteroaryl wherein the ring comprises one or more nitro groups, is boundto one or more nitro groups, or is bound to one or more side chainsbound to one or more nitro groups, wherein the group comprises only onering (Summary paragraph 11).

In certain aspects, the invention provides a composition described inany of Summary paragraphs 5-11, wherein the compound is a tobramycinderivative. In some facets, the tobramycin derivative itself exhibitsdetectably faster penetration of corneal cells than tobramycin, exhibitsdetectably better (increased) uptake or retention in corneal cells thantobramycin, or both. Thus, in such aspects, both the complexing agentwhen present, and the derivatization of the API with or without acomplexing agent, are each contributing to faster corneal cellpenetration, increased uptake or retention by corneal cells, or acombination thereof (Summary paragraph 12).

Thus, in some aspects the ophthalmic tobramycin compositions describedherein can exhibit an important advantage over conventional formulationsand are able to increase the availability of tobramycin, extendingcontact time of the same with the cornea, increasing the penetrationthrough the complex anatomical structure of the eye, and providingcontrolled release of active into the eye tissues, thus allowing for areduction in dosing frequency as will be described below; suchcompositions further addressing in certain aspects the primaryindication (e.g., microbial infection of the eye or its adnexa) or arelated indication, such as, e.g., a symptom related to infection suchas inflammation by the presence of one or more additional active agents.In aspects, the one or more additional active agents is ananti-inflammatory agent, e.g., a steroid such as dexamethasone or adexamethasone compound (Summary paragraph 13).

According to some aspects, the invention provides a pharmaceuticalcomposition of any one of (e.g., any one or more of) the precedingparagraphs, wherein a complexing agent is present and the complexingagent is a heterocyclic (e.g., a heteroaromatic) compound comprising atleast one three to seven, typically five-to-seven-member nitrogenousring comprising an attached group comprising a chain/backbone of atleast three carbons and at least one carboxylic acid group. In oneaspect, the heterocyclic ring comprises at least one nitrogen group inthe ring structure. In one aspect, the heterocyclic ring is an imidazolering. In certain aspects, the complexing agent is an amino acid, e.g.,histidine or an ophthalmologically acceptable derivative of histidine.In one aspect, the ring is a caprolactam ring. In some aspects where thecomplexing agent is a heterocyclic compound comprising at least onefive-to-seven-member nitrogenous ring comprising an attached chain of atleast three (3) carbons and at least one carboxylic acid group, thecomplexing agent is an ophthalmologically safe copolymer such aspolyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graftco-polymer (PCL-PVAc-PEG) or a derivative of PCL-PVAc-PEG (Summaryparagraph 14).

According to certain aspects, the invention provides a pharmaceuticalcomposition described in any of the preceding paragraphs, wherein theconcentration of the compound or complexed compound within thecomposition, or when the composition is present within a formulation(e.g., the compositions described above are present with one or moreexcipients), the concentration of the compound or complexed compoundwithin the formulation, is between about 0.1-about 10% w/v, such asbetween about 0.3-about 5% w/v, between about 0.6-about 5% w/v, orbetween about 1 and about 3% w/v, e.g., approximately 2.5% w/v. In somefacets, the compositions described in this paragraph comprise acomplexing agent present within the formulation at a concentration ofbetween about 0.1% and about 10% w/v, between about 0.3-5% w/v, betweenabout 0.6-5% w/v, or between about 1-3%, e.g., approximately 2.5 w/v %.According to aspects, the compositions described in this paragraphcomprise dexamethasone or a dexamethasone compound as a second activeagent, wherein the dexamethasone or a dexamethasone compound is presentwithin the composition, or also or alternatively, when the compositionis present within a formulation, the dexamethasone or a dexamethasonecompound is present within the formulation, at a concentration ofbetween about 0.01%-about 1%, such as between about 0.02%-about 0.8%,between about 0.04%-about 0.6%, between about 0.06%-about 0.4%, betweenabout 0.08%-about 0.2%, or, e.g., at a concentration of about 0.1%(Summary paragraph 15).

According to some aspects, the invention provides a pharmaceuticalcomposition described in any aspect, facet, or combination thereof ofany preceding paragraph, wherein the rate of cornea cell permeation isdetectably or significantly faster for the compound in complexed formthan the non-complexed compound, or, also or alternatively, the rate ofcornea cell permeation is detectably or significantly faster for thederivatized compound than tobramycin, such that the amount of compoundin the cornea is increased by at least about 15% or more after a periodof 60 minutes from administration (significantly in this and othercontexts means that the described effect is shown to be significantlydifferent in a sufficiently powered test/study using an appropriatetest, such as a p<0.1 or p<0.05 test). In some aspects, theconcentration of compound permeating the surface of the cornea is atleast about 17%, in some aspects at least about 20% greater, in someaspects at least about 25% greater, in some aspects at least 40%greater, and in some aspects at least 45% greater when in complexed formthan in non-complexed form or as a derivative of tobramycin thantobramycin, when measured at about 360 minutes in a corneal permeabilityassay (such as in an assay known in the art or the type of which isexemplified in the Examples provided herein). In some such aspects, theconcentration of compound permeating the surface of the cornea is atleast about 15% or greater after about 15 minutes from application thana corresponding amount of the API in TOBREX®. In certain aspects,wherein the amount of compound in the cornea is increased by at least15%, such as at least 17%, and wherein the concentration of compoundpermeating the surface of the cornea is at least about 15% or greaterafter 15 minutes from application than a corresponding amount of the APIin TOBREX®, the compound is either a derivative of tobramycin or thecompound is a complexed compound and the complexing agent is histidine.In certain alternative aspects, wherein the amount of compound in thecornea is increased by at least 15%, such as at least 17%, at least 20%,at least 25%, at least 40%, or at least 45%, and wherein theconcentration of compound permeating the surface of the cornea is atleast about 15% or greater after 15 minutes from application than acorresponding amount of the API in TOBREX®, the compound is either aderivative of tobramycin or a complexed compound and the complexingagent is PCL-PVAc-PEG. In aspects, compositions of this paragraph aretargeted to a primary indication of an eye disease, such as a microbialinfection of the eye or its adnexa, and such activity of the complexedcompounds of this paragraph is accompanied by a detectable orsignificant reduction in an indication related to the primary indicationto which the composition is targeted, such as inflammation of the eye orits adnexa, attributable to the presence of, e.g., dexamethasone or adexamethasone compound (Summary paragraph 16).

According to some aspects, the invention provides a pharmaceuticalcomposition described in any aspect, facet, or combination thereof ofany of Summary paragraphs 5-16, wherein the level of retention of thecompound or complexed compound in the cornea retained after 6 hours fromadministration when measured by a corneal retention assay. In certainaspects, a composition of any of Summary paragraphs 5-16 and in somefacets further wherein the level of retention of the compound orcomplexed compound in the cornea is retained after 6 hours fromadministration when measured by a corneal retention assay, the retentionof the compound (a derivatized tobramycin compound) or the complexedcompound within the cornea is at least 15% higher, such as at least 20%,such as at least 25%, or such as at least 30%, higher than the retentionof the non-derivatized tobramycin or the non-complexed compound whenmeasured at 360 minutes as measured by a standard corneal retentionassay. In some further aspects, the compound or complexed compound isretained in at least about 15% or greater amount in corneal cells after15 minutes than a corresponding amount of the API in TOBREX®. In somesuch facets, when the compound is present in complexed form, thecomplexing agent is histidine (Summary paragraph 17).

In some aspects, the invention provides a pharmaceutical compositiondescribed in any of Summary paragraphs 5-17, wherein the concentrationof compound or complexed compound permeating the surface of the cornea,a collection of corneal cells, or both is at least about 17% greater,such as about 20% greater in complexed form than non-complexed form, oras a derivative of tobramycin than tobramycin, when measured at 360minutes in a corneal permeability assay. In some aspects theconcentration of compound permeating the cornea or collection of cornealcells is AOA at least about 15% or greater after 15 minutes fromapplication than a corresponding amount of the API in TOBREX® (Summaryparagraph 18).

In certain facets, the invention provides a pharmaceutical compositiondescribed in any aspect or facet of Summary paragraphs 5-18, wherein therate of cornea cell permeation is detectably faster for the compound incomplexed form than the non-complexed compound, or also or alternativelythe rate of cornea cell permeation is detectably faster for a derivativeof tobramycin than tobramycin, such that the amount of compound in thecornea is increased by at least about 15% or more after a period of 60minutes from administration, and further wherein in some aspects, theconcentration of compound permeating the surface of the cornea, acollection of corneal cells, or both is at least 17% greater, in someaspects at least 20% greater, in still some further aspects at least 25%greater, such as at least 40% greater, and in further aspects at least45% greater when in complexed form than in non-complexed form or as aderivative of tobramycin than tobramycin, when measured at 360 minutesof a corneal permeability assay. In some such aspects, the concentrationof compound permeating the surface of the cornea is at least about 15%or greater after 15 minutes from application than a corresponding amountof the API in TOBREX® and when complexed the complexing agent is anophthalmologically safe derivative of PCL-PVAc-PEG having both alipophilic and amphoteric nature (Summary paragraph 19).

According to certain aspects, the invention provides a compositioncomprising an effective amount of an active pharmaceutical ingredienthaving a structure according to Formula I, wherein the compound is nottobramycin and wherein the compound is lipophilic and amphoteric innature and further wherein the composition is ophthalmologically safeand wherein the presence of any of the R groups of (1)-(4) promotes theuptake of the composition by corneal cells, the retention of thecomposition by corneal cells, or both, as compared to tobramycin, andthe composition further comprises dexamethasone or a dexamethasonecompound. In one aspect, the compound having the structure of Formula Iin the composition, the API, is a derivative of tobramycin. In oneaspect, the group of such compounds does not include tobramycin. In oneaspect, the amount of API is at least 150% that of the concentration inTOBREX®, such as at least about 200%, at least about 250%, or at leastabout 300% the amount of tobramycin in TOBREX® (Summary paragraph 20).

According to one aspect the invention provides the composition ofSummary paragraph 20, wherein the compound is a derivative oftobramycin, the derivatization of tobramycin occurs by (alternativelystated, any R group that differs from tobramycin is different fromtobramycin by) substituting a 2-20 atom backbone alkyl or heteroalkylgroup, through an ester or amide bond at a position corresponding to an—OH or —NH₂ group in tobramycin. In aspects, the alkyl or heteroalkylgroup is a linear alkyl or heteroalkyl compound. Further, in aspects thegroup generally consists of a fatty acid, a fatty acid derivative, ashort fatty acid, or a short fatty acid derivative. Still further, inaspects the group generally consist of acetic acid, an acetic acidderivative, palmitic acid, or a palmitic acid derivative. In aspectswherein the alkyl or heteroalkyl group is a linear alkyl or heteroalkylcompound, the alkyl or heteroalkyl group comprises one or more —C═O or—NH₂ derivative groups bound to the backbone. In certain aspects, thegroup comprises at least one —C═O group and at least one —NH₂ groupbound to the backbone. In aspects wherein the alkyl or heteroalkyl groupis a linear alkyl or heteroalkyl compound, the group comprises no —C═Ogroups (Summary paragraph 21).

In aspects, compositions of Summary paragraph 21, wherein the alkyl orheteroalkyl group comprises 1 or more —C═O or —NH₂ groups bound to thebackbone, and where the group comprises no —C═O groups, the groupcomprises at least 2 —NH₂ groups bound to the backbone (Summaryparagraph 22).

In facets, the invention provides a method according to any facet oraspect of Summary paragraph 21 or Summary paragraph 22, wherein thebackbone of the group is a heteroalkyl structure comprising at least onenitrogen, at least one thiol/sulfur, or both. In certain aspects, atleast about 90% of the atoms of the backbone are carbons (bound toeither hydrogen, oxygen, or other atoms as well as the other backboneatoms). In further facets, the backbone comprises or is bound to anoptionally derivatized 3-9-membered cycloalkyl or heterocycloalkyl(e.g., heteroaryl) ring. In certain such embodiments, in some aspectsthe backbone comprises or is bound to a 3-6 membered ring, such as aheterocycloalkyl or heteroaryl ring, wherein the ring comprises one ormore nitro groups, is bound to one or more nitro groups, is bound to oneor more side chains bound to or comprising one or more nitro groups, orboth (Summary paragraph 23).

According to some aspects, as described in, e.g., Summary paragraph 23the backbone of the group/structure comprises or is bound to anoptionally derivatized 3-9 membered cycloalkyl or heterocycloalkyl ring,such as a heteroaryl ring, and more specifically the backbone comprisesor is bound to a 3-6 membered ring wherein the ring comprises one ormore nitro groups, is bound to one or more nitro groups, or is bound toone or more side chains bound to or comprising one or more nitro groups,and the group/structure comprises only one ring. In some aspects, suchtobramycin derivatives exhibit detectably faster penetration of cornealcells than tobramycin, detectably better retention in corneal cells thantobramycin, or both (Summary paragraph 24).

In one aspect, the invention provides a method according to anycomposition disclosed in Summary paragraphs 20-24, wherein the compoundis complexed with a lipophilic an amphoteric complexing agent. In someaspects, the complexing agent detectably increases the permeability,retention, or both permeability and retention of the compound acrossand/or within corneal cells. In some facets, any composition describedin this paragraph comprises a complexing agent which is a heterocycliccompound comprising at least one five to seven-member nitrogenous ringcomprising an attached chain of at least 3 carbons and at least onecarboxylic acid group. In some aspects, such a complexing agent is anamino acid such as histidine or an ophthalmologically acceptablederivative of histidine having both a lipophilic and amphoteric nature.In some alternative aspects, the complexing agent is a copolymer such asPCL-PVAc-PEG or an ophthalmologically safe derivative of PCL-PVAc-PEGhaving both a lipophilic and amphoteric nature (Summary paragraph 25).

In certain facets, the invention provides any method described inSummary paragraphs 20-25, wherein the compound is present within theformulation in a concentration of between about 0.1-about 10% w/v, suchas in some aspects between about 0.3-about 6% w/v, such as in someaspects between about 0.6-about 6% w/v, as in in some aspects betweenabout 1% and about 3% w/v (or about 1-3.5% or 1.5%-3.5% w/v), as in forexample in some aspects approximately 2.5% w/v. According to any suchfacet, in some aspects if the formulation comprises a complexing agent,the complexing agent AOA is present in the formulation in aconcentration ranging from 0.1-10% w/v, such as in any of theabove-described ranges. In one aspect, the ratio of complexing agent toAPI is AOA about 0.5:1 to about 2:1 by weight or w/v, such as about0.75:1 to about 1.25:1 w/v, such as about 0.9:1 to about 1.1:1 w/v orabout 1:1 w/v. According to aspects, the compositions described in thisparagraph comprise dexamethasone or a dexamethasone compound as a secondactive agent, wherein the dexamethasone or a dexamethasone compound ispresent within the composition, or also or alternatively, when thecomposition is present within a formulation, the dexamethasone or adexamethasone compound is present within the formulation, at aconcentration of between about 0.01%-about 1%, such as between about0.02%-about 0.8%, between about 0.04%-about 0.6%, between about0.06%-about 0.4%, between about 0.08%-about 0.2%, or, e.g., at aconcentration of about 0.1%. In aspects, the ratio of the amount ofcompound to the amount of dexamethasone or a dexamethasone compound isabout 50:1, such as about 40:1, 30:1, about 20:1, or about 10:1, such asbetween about 15-30:1, as in, e.g., about 25:1 (Summary paragraph 26).

In some aspects, the invention provides a composition described in anyof Summary paragraphs 20-26, wherein the rate of cornea cell penetrationof the compound is detectably faster or significantly faster than thatof tobramycin, a current formulation of tobramycin, or both. In one suchaspect, the amount of the tobramycin derivative compound in the corneais increased by at least about 15% or more after a period of 360 minutesfrom administration as compared to a substantially identical compositioncomprising a substantially identical amount of tobramycin. In certainaspects, the concentration of compound permeating the surface of thecornea or collection of corneal cells in a test method/standard is atleast about 17% greater, in some facets at least about 20% greater, insome facets at least about 25% greater, in some aspects at least about40% greater, and in some aspects at least about 45% greater thantobramycin when measured at 360 minutes in a corneal permeability assay(Summary paragraph 27).

In some aspects, the invention provides a composition described in anyof Summary paragraphs 20-27, wherein the level of retention of thecompound (or compound complex if a complexing agent is present) withinthe cornea after 6 hours from administration when measured at 360minutes in a standard corneal retention assay is significantly greaterthan the level of tobramycin when administered in a substantiallyidentical formulation in a substantially identical amount. The phrasesubstantially identical is used in this and other contexts to reflectthat tests that would be considered substantially identical by those ofskill in the art can be acceptable for assessing/defining such anaspect. It will be appreciated that the phrase “substantially identical”in such contexts comprises the use of identical amounts, identicalformulations, and identical conditions in other respects (Summaryparagraph 28).

In some aspects, the invention provides a composition described in anyof Summary paragraphs 20-26, wherein the compound (or compound complexif a complexing agent is present) is retained in at least about 15% orgreater amount in the cornea or corneal cells after 15 minutes than acorresponding amount of the API in TOBREX® when similarly administered.In certain aspects, the retention of the compound within the cornea orcorneal cells as measured by a standard corneal retention assay is atleast about 15% higher, such as in some aspects about 17% higher, as inin some aspects about 20% higher, as in in certain facets at least about25% higher, such as in certain facets about 30% higher, or such as insome aspects at least about 32% higher than the retention of tobramycinin the same assay (Summary paragraph 29).

In some aspects, the invention provides a pharmaceutical formulationcomprising an active pharmaceutical agent according to any one of (e.g.,any one or more of) the preceding paragraphs, wherein the formulationcomprises an effective amount of one or additional delivery agentsselected from one or more liposome(s), microsphere(s), or both, which isamphoteric, lipophilic, and suitable for ophthalmologic applications,wherein the compound (or compound complex if a complexing agent ispresent) is retained in at least about 15% greater amount in cornealcells after 15 minutes than a corresponding amount of the compound whenno additional delivery agent is present. In certain facets, the presenceof the one or more additional delivery agents detectably orsignificantly enhances the permeation, retention, or both permeation ofretention of the compound across and/or within corneal cells compared toa similar formulation comprising no such additional delivery agents. Insome facets, such formulations further comprise one or more excipients,such as for example one or more excipients is selected from the groupcomprising one or more of a viscosity-enhancer, osmotic modificationagent, surfactant, chelating agent, tonicity agent, buffer, pH-adjustingagent, a preservative, or water. In certain facets, at least oneexcipient is a viscosity enhancing excipient and in certain aspects theviscosity of the formulation is between about 10 cps and about 400 cps,such as for example a viscosity of about 25 cps to about 300 cps. Incertain aspects, the viscosity is at least 5% higher than the viscosityof a similar composition which does not comprise a viscosity enhancingagent. Further, such compositions comprise a one or more additionalactive agents, such as an anti-inflammatory agent, e.g., a steroid suchas dexamethasone or a dexamethasone compound (Summary paragraph 30).

In some aspects, the invention provides a formulation described in anyaspect or facet or combination thereof of Summary paragraph 29, whereinthe compound or compound complex is present in the formulation in aconcentration of between about 0.1-about 10% w/v, such as for example insome aspects between about 0.3-about 5% w/v, such as in some aspectsbetween about 0.6-about 5% w/v, as in in some facets between about 1 andabout 3% w/v, such as in some facets approximately 2.5% w/v. Accordingto some aspects, the complexing agent is present within the formulationin a concentration of between about 0.1-about 10% w/v, such as forexample in some aspects between about 0.3-5% w/v, such as for example insome aspects between about 1-5% w/v, as in in some aspects approximately2.5% w/v. In aspects a dexamethasone compound is present in theformulation in an amount of between about 0.01%-about 1%, such asbetween about 0.02%-about 0.8%, between about 0.04%-about 0.6%, betweenabout 0.06%-about 0.4%, between about 0.08%-about 0.2%, or, e.g., in anamount of about 0.1% (Summary paragraph 31).

According to some facets, the invention provides a pharmaceuticalformulation comprising a composition comprising a pharmaceuticallyactive ingredient comprising a compound having a structure according toFormula I, wherein the compound is not tobramycin; wherein the compoundis lipophilic and amphoteric in nature; wherein the composition isophthalmologically safe; wherein the presence of any of the R groups of(1)-(4) promotes the uptake of the composition by corneal cells, theretention of the composition by corneal cells, or both, as compared totobramycin; wherein the formulation comprises an effective amount of oneor additional delivery agents selected from a liposome(s), amicrosphere(s), or both, which is amphoteric, lipophilic, and suitablefor ophthalmologic applications; wherein the compound is retained in atleast about 15% greater amount in corneal cells after 15 minutes than acorresponding amount of the compound when no additional delivery agentis present; and, further, wherein the formulation comprises one or moreadditional active agents such as an anti-inflammatory agent, such as asteroid, e.g., a dexamethasone compound. In certain aspects, the primarycompound is a derivative of tobramycin. In some aspects, the group ofprimary compounds so defined in this paragraph does not includetobramycin, and in other aspects it includes tobramycin (Summaryparagraph 32).

According to some aspects, the invention provides a pharmaceuticalformulation of Summary paragraph 32, wherein the derivatization oftobramycin occurs by (alternatively stated, any R group that differsfrom tobramycin is different from tobramycin by) substituting a 2-20atom backbone alkyl or heteroalkyl group, e.g., through an ester oramide bond, at a position corresponding to an —OH or —NH₂ group intobramycin. In some aspects, the alkyl or heteroalkyl group comprises,primarily comprises, generally consists of, or consists of a linearalkyl or heteroalkyl compound. In some further aspects, the groupgenerally consists of a fatty acid (e.g., a C₁₂-C₁₈ fatty acid), a fattyacid derivative, a short fatty acid (e.g., a C₂-C₄ fatty acid), or ashort fatty acid derivative. In some still further facets, the groupgenerally consist of acetic acid, an acetic acid derivative, palmiticacid, or a palmitic acid derivative (Summary paragraph 33).

In aspects, the invention provides a formulation of Summary paragraph33, wherein the alkyl or heteroalkyl group is a linear alkyl orheteroalkyl compound wherein the alkyl or heteroalkyl group comprisesone or more —C═O or —NH₂ groups bound to the backbone. In certainfacets, the group comprises at least one —C═O group and at least one—NH₂ group bound to the backbone. In some aspects wherein the alkyl orheteroalkyl group is a linear alkyl or heteroalkyl compound wherein thealkyl or heteroalkyl group comprises one or more —C═O or —NH₂ derivativegroups bound to the backbone, the group comprises no —C═O groups. Insome aspects, the invention provides a compound having such a formulawherein the group comprises at least two —NH₂ groups bound to thebackbone. In some further aspects, the backbone of the group is aheteroalkyl structure comprising at least one nitrogen, at least onethiol/sulfur, or both. In some still further facets, at least about 90%of the atoms of the backbone are carbons. According to some yet furtheraspects, the backbone comprises or is bound to an optionally derivatized3-9-membered cycloalkyl or heterocycloalkyl ring (e.g., a heteroarylring, such as a heteroaryl ring comprising one or more nitrogen groups,such as 1-4 nitrogen groups). In such cases, in some facets, thebackbone comprises or is bound to a 3-6 membered ring wherein the ringcomprises one or more nitro groups, is bound to one or more nitrogroups, is bound to one or more side chains bound to one or more nitrogroups, or comprises a combination of any or all thereof. In certainrelated aspects, the group(s) bound to the backbone comprise(s) only onering. In some aspects, the described formulations provide a tobramycinderivative which exhibits detectably faster penetration of corneal cellsthan tobramycin, detectably better retention in corneal cells thantobramycin, or both (Summary paragraph 34).

In some aspects, the invention provides a formulation described inSummary paragraphs 32-34, wherein the compound is complexed with alipophilic and amphoteric, complexing agent. In certain aspects, thecomplexing agent detectably increases the permeability, retention, orboth permeability and retention of the compound across and/or withincorneal cells, and further the formulation comprises dexamethasone or adexamethasone compound (Summary paragraph 35).

In some facets, the invention provides a formulation described inSummary paragraph 33, wherein the complexing agent is a heterocycliccompound comprising at least one five-to-seven-member nitrogenous ringcomprising an attached chain of at least 3 carbons and at least onecarboxylic acid group. In certain facets, the complexing agent is anamino acid, such as, e.g., histidine or an ophthalmologically acceptablederivative of histidine having both a lipophilic and amphoteric nature.In certain facets, the complexing agent is a copolymer, such asPCL-PVAc-PEG or an ophthalmologically safe derivative of PCL-PVAc-PEGhaving both a lipophilic and amphoteric nature (Summary paragraph 36).

In some aspects, the invention provides a formulation described in anyof Summary paragraphs 32-36, wherein the presence of the one or moreadditional delivery agents significantly enhances the permeation,retention, or both permeation and retention of the compound acrossand/or within corneal cells compared to a similar formulation comprisingno additional delivery agents. In certain facets, such formulationsfurther comprise one or more excipients, such as e.g., one or moreexcipients selected from the group comprising one or more of aviscosity-enhancer, osmotic modification agent, surfactant, chelatingagent, tonicity agent, buffer, pH-adjusting agent, a preservative, orwater. In certain facets at least one excipient is a viscosity enhancingexcipient, and, in some facets, the viscosity of the formulation isbetween about 10 cps and about 400 cps, such as for example in somefacets about 25 cps to about 300 cps. In some facets, the viscosity isat least 5% higher than the viscosity of a similar composition whichdoes not comprise a viscosity enhancing agent. In aspects, theformulation comprises dexamethasone or a dexamethasone compound as oneof one or more additional active agents (Summary paragraph 37).

In some aspects, the invention provides a formulation described in anyof Summary paragraphs 32-37, wherein the compound (or as applicable thecomplexed compound) is present in the formulation in a concentration ofbetween about 0.1-about 10% w/v, such as in some aspects between about0.3-about 5% w/v, such as in some aspects between about 0.6-about 5%w/v, as in in some facets between about 1 and about 3% w/v, such as insome aspects approximately 2.5% w/v. In certain such formulations, insome aspects the complexing agent, when present, is present in theformulation in a concentration of between about 0.1-10% w/v. In aspects,such formulations further comprise dexamethasone or a dexamethasonecompound in an amount of between about 0.01-1% w/v (Summary paragraph38).

According to some aspects, the invention provides a pharmaceuticalformulation comprising an antimicrobial active pharmaceutical ingredientcomprising an effective amount of a compound having a structureaccording to Formula I and an effective amount of a liposome ormicrosphere delivery agent, which is amphoteric, lipophilic, andsuitable for ophthalmologic applications, wherein the compound isretained in at least about 15% greater amount in corneal cells after 15minutes than a corresponding amount of the compound when not presentwith the liposome or microsphere delivery agent, and wherein thecompound is not tobramycin. In some aspects, the compound is present ina composition in an amount that is at least about 150%, at least about200%, at least about 250%, or at least about 300% of the currentconcentration of tobramycin in TOBREX®. Further, such formulations cancomprise dexamethasone or a dexamethasone compound in an amount whereinthe ratio of the primary compound or compound complex to dexamethasoneor dexamethasone compound is between about 50:1-about 1:1, such asbetween about 40:1-about 10:1, between about 30:1-about 20:1, or in aratio of about 25:1 (Summary paragraph 39).

According to some aspects, the invention provides a formulation asdescribed in Summary paragraph 39, wherein the primary compound/API iscomplexed with a complexing agent comprising a heterocyclic (e.g.,heteroaryl) compound comprising at least one five to seven membernitrogenous ring comprising an attached chain of at least 3 carbons andat least one carboxylic acid group. In some aspects, the complexingagent is an amino acid such as histidine or an ophthalmologicallyacceptable derivative of histidine having both a lipophilic andamphoteric nature, and that detectably or significantly enhances thespeed of uptake of the complex by corneal cells, the uptake/retention ofthe complex by corneal cells, or both. In certain alternative aspects,the complexing agent is a copolymer, such as PCL-PVAc-PEG or anophthalmologically safe derivative of PCL-PVAc-PEG having both alipophilic and amphoteric nature and that detectably or significantlyenhances the speed of uptake of the complex by corneal cells, theuptake/retention of the complex by corneal cells, or both. In certainfacets, the presence of the complexing agent significantly enhances thepermeation, retention, or both permeation and retention of the compoundacross, within, or both across and/or within corneal cells compared to asimilar formulation comprising no complexing agent (Summary paragraph40).

In certain aspects, the invention provides a formulation described inany of Summary paragraphs 39-40, wherein the formulation furthercomprises one or more excipients that provide one or more properties tothe formulation, such as a preservative function, a buffering function,and the like. In one aspect, the one or more excipients is selected fromthe group comprising one or more of a viscosity-enhancer, osmoticmodification agent, surfactant, chelating agent, tonicity agent, buffer,pH-adjusting agent, a preservative, or water. In some facets, at leastone excipient is a viscosity enhancing excipient. According to someaspects, the viscosity of the formulation is between about 10 cps andabout 400 cps, such as for example a viscosity of about 25 cps to about300 cps. In certain facets, the viscosity is at least about 5% higher(e.g., at least about 7% higher, at least about 10% higher, or at leastabout 15% higher) than the viscosity of a similar composition which doesnot comprise the viscosity enhancing agent or any viscosity enhancingagent. Further, such formulations comprise dexamethasone or adexamethasone compound as one of one or more additional active agents(Summary paragraph 41).

According to some facets, the invention provides a formulation describedin any of Summary paragraphs 39-41, wherein the primary compound orcompound complex is present in the formulation in a concentration ofbetween about 0.1-about 10% w/v, such as in some aspects between about0.3-about 5% w/v, such as in some aspects between about 0.6-about 5%w/v, as in in some facets between about 1 and about 3% w/v, such as insome aspects approximately 2.5% w/v, in certain facets, the complexingagent, when present, is present in the formulation in a concentration ofbetween about 0.1-10% w/v (e.g., about 0.05-0.25% w/v or about 0.9-9%w/v or about 1.2-7.2% w/v), and in aspects dexamethasone is present inthe formulation in an amount of between about 0.01-1% (e.g., betweenabout 0.05-0.5%) (Summary paragraph 42).

According to certain aspects, the invention provides a formulationdescribed in any facet, aspect, or combination thereof described in anyof Summary paragraphs 30-42, wherein the compound is retained in atleast about a 15% greater amount in corneal cells after 15 minutes thanthe API in TOBREX® as measured by a corneal cell retention assay. Insome aspects, any of the formulations described in any of the aboveparagraphs is/are delivered as a solution, emulsion, dispersion, orsuspension. In some facets, the formulation is delivered as a solution,and in further facets, can be administered via drops to the eye. Incertain alternative aspects, the formulation is delivered as anointment, and in further aspects, can be administered by applying astrip of the ointment to the eye. In certain embodiments, any of theformulations described by this paragraph maintain the compound incontact with the ocular surface (mucous membrane) of the eye for atleast 2 hours after application, such as in some aspects for at leastapproximately 4 hours after application, such as in some aspects for atleast approximately 8 hours after application, as in in some facets forat least approximately 16 hours after application, as in in some aspectsfor at least approximately 20 hours after application, or such as incertain aspects for at least approximately 24 hours after application(Summary paragraph 43).

According to some aspects, the invention provides a formulationdescribed by any aspect, facet, or combination of aspects and facetsdescribed in Summary paragraphs 30-43, wherein the formulation comprisesone or more additional active pharmaceutical ingredients (APIs). Inaspects, the API is an anti-inflammatory. In certain further facets, theadditional active AOA is a steroid, such as, e.g., dexamethasone. Instill another aspect, the additional active AOA includes at least oneadditional antibiotic. In one aspect, a composition is provided andmethods are provided wherein two different compounds according toFormula I, Formula II, or Formula III are administered in association orare co-formulated and/or co-administered Summary paragraph 44).

In this and in other respects, the ophthalmic tobramycin compositionsdescribed herein can exhibit important advantages and differences overconventional ophthalmologic tobramycin products and formulations, suchas, in some aspects, being able to increase the availability oftobramycin or a tobramycin derivative, extending residence time of suchAPIs with the cornea, increasing the penetration through the cornea, orproviding controlled release of active into the eye tissues, leading todifferent or improved properties and applications. These and otherproperties of the compositions of the invention and methods of usingsuch compositions are described below in the Detailed Description of theInvention part of this disclosure (Summary paragraph 45).

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

The drawings/figures provided here, and the associated following briefdescription of figures, are intended to exemplify certain aspects andprinciples of the invention, without limiting the scope of eitherthereof.

FIGS. 1A-1D are differential Scanning Colorimetry (DSC) spectra oftobramycin (FIG. 1A), histidine (FIG. 1B), a tobramycin+histidinephysical mixture (FIG. 1C), and a tobramycin+histidine complex accordingto one aspect of the invention (FIG. 1D).

FIGS. 2A-2C are Fourier transform infrared (FTIR) spectra of tobramycinand histidine, each individually (FIGS. 2A and 2B), and atobramycin+histidine complex of one aspect of the invention (FIG. 2C).

FIGS. 3A-3D are DSC spectra of tobramycin (FIG. 3A), Soluplus® (FIG.3B), tobramycin+Soluplus® physical mixture (FIG. 3C), and atobramycin+Soluplus® complex according to an aspect of the invention(FIG. 3D).

FIGS. 4A-4C are FTIR spectra of tobramycin and Soluplus® eachindividually (FIGS. 4A and 4B) and a tobramycin+Soluplus® complex. (FIG.4C).

FIG. 5 is a graph showing the corneal permeability of tobramycin,tobramycin+histidine complex solution and tobramycin+Soluplus® complexsolution.

FIG. 6 is a plot showing the depletion rate of tobramycin, atobramycin+histidine complex solution, and a tobramycin+Soluplus®complex solution, in each applicable donor chamber, in a depletionassay.

FIG. 7 is a graph of the number of S. Aureus colony forming units (CFUs)in tear sample(s) after 2 doses of a reference formulation versusvehicle.

FIG. 8 is a graph of the number of S. Aureus colony forming units (CFUs)in tear sample(s) after 2 doses of tobramycin (0.3%)+histidine (0.3%)versus vehicle.

FIG. 9 is a graph of the number of P. Aeruginosa colony forming units(CFUs) in tear sample(s) after 2 doses of reference formulation versusvehicle.

FIG. 10 is a graph of the number of P. Aeruginosa colony forming units(CFUs) in tear sample(s) after 2 doses of tobramycin (0.3%)+histidine(0.3%) versus vehicle.

FIG. 11 is a graph of the number of P. Aeruginosa colony forming units(CFUs) in tear sample(s) after 2 doses of tobramycin (0.6%)+histidine(0.6%) versus vehicle.

DETAILED DESCRIPTION OF THE INVENTION Construction, Definitions, &Acronyms

To aid in the understanding of the disclosure provided herein, thefollowing principles should be considered.

“Uncontradicted” means not contradicted explicitly, clearly by context,or by inoperability/impossibility.

Terms such as “here” & “herein” means “in this disclosure.” Except whereotherwise specified, any part if this disclosure is applicable to anyother suitable part of the disclosure.

The invention described here includes several aspects. Uncontradicted,“aspects,” means “aspects of this invention.” The “invention”encompasses all aspects herein, individually & collectively (methods anddevices/systems/compositions).

Heading(s) here are used for convenience only. Except where clearlyotherwise indicated, aspects under a heading can be combined with otheraspects described in any section of the disclosure. Heading(s) do notlimit the scope of any aspect.

Uncontradicted, “a,” “an,” “the,” and similar referents indicate boththe singular and the plural of any associated element. Uncontradicted,terms in the singular implicitly convey the plural and vice versa here(e.g., a passage referring to use of an “element” implicitly disclosesuse of corresponding “elements”). Uncontradicted, “also” means “also oralternatively.” The “I” symbol is sometimes used to indicate an “or”relationship between elements (e.g., “A/B” means “A or B”). A slashsymbol can also indicate an element with two names. Terms like“combination,” “and combinations,” or “or any combinations” regardinglisted elements mean “a combination of any or all of such elements.”

Uncontradicted, each member of each list of elements reflects anindependent aspect (often having distinct/nonobvious properties withrespect to the other listed elements/aspects or features).

Ranges here concisely refer to values within the range within an orderof magnitude of the smallest endpoint. E.g., readers should interpret“1-2” as implicitly disclosing each of 1.0, 1.1, 1.2, 1.3, 1.4, 1.5,1.6, 1.7, 1.8, 1.9, & 2.0, “5-20” as implicitly disclosing each of 5,5.1, 5.2, . . . , 6, 6.1, 6.2, . . . 19, 19.1, . . . , 19.9, and 20, and“10-20” is to be interpreted as implicitly providing support for each of10, 11, 12, 13, . . . , 19, & 20. Ranges here include end points,regardless of how the range is described (e.g., a range “between” 1 and5 will include 1 and 5 in addition to 2, 2.1, . . . , 3, 3.1, . . . , 4,4.1, . . . , and 4.9), unless the exclusion of such endpoints is clearlyindicated, regardless of the terminology used to describe the range.Uncontradicted, applying a modifier to 1 or 2 endpoints does not changethe range's value (e.g., “about 10-20” means “about 10-about 20”).

Terms of approximation, e.g., “about” or “approximately” (or ˜) hererefer to a range of closely related values, value(s)difficult/impossible to precisely measure, or both, and, thus, includethe precise value as an aspect of the disclosure (e.g., “10” is anaspect of a disclosure of “about 10”). Similarly, precise valuesprovided here support approximately similar ranges unless contradicted.The scope of an approximate value depends on the value, context, andtechnology (e.g., criticality or operability, other evidence,statistical significance, or general understanding). In the absence ofguidance here or in the art, terms of approximation such as “about” or“approximately” mean+/−10% of the indicated value(s).

Uncontradicted, “or” means “and/or” here. The occasional explicit use of“and/or” herein has no effect on this interpretation of “or.”Uncontradicted, the scope of “or” meaning “and/or” in a phrase such as“A, B, and/or C” or “A, B, and C” implicitly supports each of thefollowing embodiments: A, B, and C; A, B, or C; A or C; A or B; B or C;A and C; A and B; B and C; A (alone); B (alone); and C (alone).Uncontradicted, methods described here be performed in any suitableorder. Uncontradicted, devices/compositions can be assembled/generatedin any suitable manner by any suitable method. Uncontradicted, anycombination of elements, steps, components, or features of aspects andapparent variations thereof, each constitute separate aspects of theinvention.

Numerous examples of aspects, elements, or steps are provided in thisdisclosure to illuminate aspects. The breadth and scope of the inventionshould not be limited by any such exemplary elements or embodiments. Nolanguage in the specification should be construed as indicating anyelement is essential to the practice of the invention unless such arequirement is explicitly stated.

Although this document provides support for “means-plus-function” styleinterpretation of certain elements of the invention, both explicitly andimplicitly, unless “means for” or “step for” are used here, no elementshould be given a “means-plus-function” construction. Terms like“configured to” or “adapted to” are not “means-plus-function” terms,but, rather, refer to features configured, designed, selected, orotherwise adapted to achieve a performance, characteristic, property, orthe like using this disclosure and technology.

The description herein of any aspect or embodiment using terms such as“comprising”, “having,” “including,” or “containing” with reference toan element, composition, or set of compositions or elements should beinterpreted, whether explicitly stated or not, as simultaneouslyproviding support for a similar aspect or embodiment that “consists of”,“substantially comprises,” “materially comprises,” “predominatelycomprises,” “largely consists of,” and “substantially consists of” thatparticular element, unless otherwise stated or clearly contradicted bycontext (i.e., a composition described herein as comprising a particularelement should be understood as also describing a composition consistingof that element, substantially comprising that element, predominatelycomprising that element, largely consisting of that element, andsubstantially consisting of that element, unless otherwise stated orclearly contradicted by context). Terms such as “including”,“containing”, and “having” should otherwise be interpreted openlyherein, e.g., as meaning “including, but not limited to”, “including,without limitation”, or “comprising”, unless otherwise such a meaning isclearly contradicted.

The term “substantially comprises” means that at least about 1% of acomposition, population, or similar collection is or is made up of/bythe referenced feature, species, or element, and typically means (andshould be understood as providing support for) the relevant featuremakes up or represents at least about 5%, at least about 10%, or even atleast about 15% of the total amount of the composition or number of thepopulation.

“Materially comprises” means that at least about 20% of a composition,population, or similar collection is or is made up of/by the referencedfeature, species, or element, and typically means (and should beunderstood as providing support for) the relevant feature makes up orrepresents at least about 25%, at least about 30%, or even at leastabout 40% of the total amount of the composition or number of thepopulation.

“Predominately comprises” means accounting for more than one half (i.e.,more than 50%) of a feature (e.g., a composition or a population ofthings). This amount and similar amounts used in respect of definedterms provided herein can be on a weight percent (weight/weight) basis,on a molecule/molecule basis, or other relevant basis used in thecontext of the relevant disclosure. For example, if a composition isdescribed as “predominately comprising” element/species A, more than 50%of the composition on a molecular and/or weight basis will be made up ofelement/species A). Wherever this term is used it should be understoodas simultaneously providing support for more than 60%, more than 70%,and more than 80% of the component or composition or collection beingmade up of the feature, species, or element at issue. The term “most”should also be construed similarly herein.

“Largely consists of” means that at least about 75% of the composition,population, or the like is or is made up of the referenced feature,species, or element at hand and should be understood as providingdisclosure that at least 82.5%, at least 87.5%, at least 92.5%, and atleast 97.5% of the composition, population, or the like is or is made upof/by the referenced feature, species, or element. Obviously, theremaining minority portion of the relevant composition, collection, andthe like can be composed of other compounds, materials, or otherrelevant elements. The phrases “largely all” and “largely most” shouldbe construed similarly.

“Substantially consists of” means at least ˜90% of the composition,population, or the like is made up of the referenced feature, species,or element and should be understood as also providing disclosure that atleast ˜95%, at least ˜99%, or at least ˜99.9% of the composition,collection, etc., is made up of the relevant element, feature, or thing.The phrases “nearly all” and “nearly entirely” should be construedsimilarly.

Changes to tense or presentation of terms (e.g., using “comprisespredominately” in place of “predominately comprises”) do not modify themeaning of the related phrase unless indicated. “Significant” and“significantly” means results/characteristics that are statisticallysignificant using an appropriate test in the given context (e.g.,p≤0.05/0.01). “Detectable” means measurably present/different. Theabbreviation “DOS” means “detectable or significant” or “detectably orsignificantly.”

The intended audience for this disclosure (“readers”) are persons havingordinary skill in the art in the practice of the technologies discussedherein (“skilled persons”). Technological aspects of elements/stepsprovided here are sometimes omitted in view of the knowledge of readers.The terms “technology” and “art” here refer to the knowledge of suchskilled persons. In cases, citation of reference(s) adaptable to aspectsare included here. All such patent documents and other publications arehereby incorporated by reference to the same extent as if each referencewere individually and specifically indicated to be incorporated byreference and were set forth in its entirety herein. The disclosure ofsuch references can be combinable with this disclosure; however,incorporation of patent documents is limited to the technical disclosurethereof and does not reflect on validity, patentability, orenforceability thereof. Moreover, in the event of any conflict betweenthis disclosure and the teachings of such documents, the content of thisdisclosure will control with respect to properly understanding variousaspects. Readers will also understand that some features of some citedreferences are not applicable to aspects.

Unless clearly indicated, the scope of any aspect or embodiment is notlimited to processes, compositions, or methodologies described, as thesemay vary. The terminology used in the description is for the purpose ofdescribing particular versions or embodiments only; and is not intendedto limit the scope of any aspects. Unless defined otherwise, alltechnical and scientific terms used herein have the same meanings ascommonly understood by one of ordinary skill in the art. Any methods andmaterials similar or equivalent to those described herein can be used inthe practice or testing of embodiments of the invention, the methods,devices, and materials described herein.

The description of the specific embodiments provided herein will revealthe general nature of the invention such that others can, by applyingknowledge within the skill of the art, readily modify and/or adapt forvarious applications such specific embodiments, without undueexperimentation, without departing from the general concept of theinvention. Therefore, such adaptations and modifications are intended tobe within the meaning and range of equivalents of the disclosedembodiments, based on the teaching and guidance presented herein. Ingeneral, it is to be understood that the phraseology or terminologyherein is for the purpose of description and not of limitation, suchthat the terminology or phraseology of the present specification is tobe interpreted by the skilled artisan in light of the teachings andguidance.

Compounds of the Invention

Provided here are compositions comprising one or more pharmaceuticallysuitable and pharmaceutically active compounds which, in some facets,are or are identifiable as being closely related to compounds of theaminoglycoside 4,6-disubstituted deoxystreptamine sub-class. In aspects,such compounds comprise tobramycin or a compound similar to tobramycin.In aspects, such compounds are referred to as a “primary compound”herein, as such compounds can be present in a formulation which furthercomprises one or more excipients or one or more additional activepharmaceutical ingredients. In aspects, the compounds described hereinare derivatized analogues of tobramycin wherein, e.g., any one or morehydroxy groups or amide groups present on the naturally occurringcompound are substituted with one or more groups that are lipophilic,amphoteric, ophthalmologically acceptable, and which do not significantreduce the antibiotic properties of the compound as compared totobramycin, or that also enhance the ability of the compound topenetrate corneal cells faster, penetrate in higher concentrations(e.g., an increased amount of the compound is capable of penetrating),or be retained in corneal cells in higher concentrations, or any or allthereof, as compared to tobramycin. Such an increase in thepermeability, uptake, retention, or any combination of permeability(rate or concentration as described above), uptake, or retention of thecompounds described herein by the cornea provide an opportunity forbeneficial improvements in active concentration and dosing regimens overcurrently available tobramycin treatments, yielding further improvementin clinical outcome measures (e.g., efficacy) or patient experience(e.g., improved tolerability, compliance) as is described herein. Inaspects, non-complexed, derivatized compounds of the invention canprovide similar or equivalent corneal cell penetration, similar orequivalent corneal cell penetration rates, similar or equivalent cornealcell retention, or any combination thereof, to complexed compounds, suchcorneal cell penetration, penetration rates, and retention of suchcomplexes described herein. In aspects, corneal cell penetration,penetration rates, and retention of non-complexed, derivatizedtobramycin compounds described herein are higher than that ofnon-derivatized tobramycin.

The term “tobramycin” generally can be interpreted to refer totobramycin in any suitable form, including any pharmaceuticallyacceptable salts, pharmaceutically acceptable solvates, pharmaceuticallyacceptable hydrates, and the like that one of ordinary skill would viewas substitutable for another form of tobramycin. When making acomparison of the activity, efficacy, or other quality of thecompositions or compositions of the invention to on-market products,such as a comparison of the compositions described herein to TOBREX® orTOBRADEX ST® or the compounds herein the to the API of TOBREX® orTOBRADEX ST®, it should be understood that such disclosure encompassessuch comparison(s) to similar or equivalent on-market products, such asan equivalent generic product or a composition having a shared activeingredient for similar applications. In aspects, the tobramycin ofcompositions comprises a compound comprising the same basic structure oftobramycin in these compositions.

In general, the compounds disclosed herein find particular use inophthalmological conditions. Such compounds are pharmaceuticallyacceptable, and effective as antibiotics in the eye. Further descriptionof such characteristics associated with all, several, and some of thecompounds of the invention are included herein.

As noted above, tobramycin (full chemical name0-{3-amino-3-deoxy-α-D-gluco-pyranosyl-(1→4)}-0-{2,6-diamino-2,3,6-trideoxy-α-D-ribohexo-pyranosyl-(1→6)}-2-deoxystreptamine(structure shown below) is an FDA approved aminoglycoside for thetreatment of external eye infections. It is a highly water-solubleaminoglycoside, having a solubility in water of 94 mg/mL and a logpartition coefficient of −5.8. It has antibiotic activity against a widevariety of gram-negative and gram-positive ophthalmic pathogens.Tobramycin has the following structure:

The invention provides complexes that comprise a tobramycin compound,such as tobramycin, and exhibit different or improved properties ascompared to noncomplexed tobramycin compounds, such as counterparttobramycin compounds, e.g., in terms of the ability of the complexedcomposition to permeate corneal cells, be retained or taken up by suchcorneal cells, or both, and novel functional formulations that alsoinclude tobramycin and achieve similar results.

The invention also includes derivatives of tobramycin that can achievethese properties, independent of any complexing agent or formulation.

In aspects, a tobramycin derivative, such as a tobramycin derivativewith such above-described properties, can be further combined with acomplexing agent, functional formulation, or both, with the propertiesof the derivative, complexing agent, or functional formulation allcontributing to an enhanced ability to permeate corneal cells, beretained or taken up by corneal cells, or both.

In one aspect, compounds that are provided herein or that can becontained in a complex or functional formulation provided hereincomprise a structure according to the formula below:

wherein R¹-R¹⁰ are as described in the following paragraphs below(Formula I).

In certain aspects, position R¹ is —CH—NH₂ (i.e., Me—NH₂). In certainalternative aspects, position R¹ is substituted with a group selectedfrom the group comprising a/an optionally substituted alkyl, aryl,aralkyl, cycloalkyl, cycloalkylalkyl, heterocyclyl, heterocyclylalkyl,heteroaryl, or heteroarylalkyl. The term optionally substituted in sucha phrase is intended to apply to all members of the listed group(including, e.g., cycloalkylalkyl and heteroaryl). The use ofoverlapping groups/terms above and in other aspects of this disclosureis not intended to apply any exclusion. Thus, for example, althoughheterocyclyl and heteroaryl are both recited above and in other listsherein, it will be understood that reference to a heterocyclylencompasses both aromatic and nonaromatic heterocyclic compounds unlessotherwise stated or clearly indicated by the disclosure.

Chemical terminology, such as to describe various R groups of compounds,is well understood in the art and, as such, only general guidance isprovided here to clarify the scope of certain aspects and to provideexamples to better illuminate this disclosure. Where those of skill inthe art would understand such terms to encompass groups not exemplifiedor other scope not described, such additions to the terms providedherein should be considered within the broadest scope of this disclosureas an additional facet of the described composition, method, orcompound. Given the knowledge in the art not all terms used in thedisclosure may be specifically described here, but such terms willnonetheless be understood by the skilled reader given ordinary practicein the art.

The term “alkyl” typically refers to a group having the general formulaC_(n)H_(2n+1), wherein the hydrocarbon chain is straight or branchedcontaining only carbon and hydrogen atoms; simply for group definitionpurposes, examples include methyl CH₃ (derived from methane) and butylC₂H₅ (derived from butane). In one aspect such alkyl groups will containfrom between one and 12 carbon atoms (C₁-C₁₂ alkyl), such as, forexample 1-12, 1-8, or 1-6 carbon atoms, and which is attached to therest of the molecule by a single bond.

The term “aryl” typically refers to any functional group or substituentcomprising or derived from an aromatic ring, for example an aromatichydrocarbon; simply for group definition purposes, a simple exemplaryaryl group is phenyl C₆H₅. In aspects, aryl groups can contain between6-18 carbon atoms (e.g., 6-18, 10-18, 14-18, or for example 6-14, 6-12,or 6-8 carbon atoms) along with the at least one aromatic ring.

An “aralkyl” typically refers to a univalent radical derived from analkyl radical by replacing one or more hydrogen atoms by aryl groups (anaryl-substituted alkyl radical, or alternatively stated, a radical inwhich an aryl group is substituted for a hydrogen atom of an alkylgroup).

As used herein, “cycloalkyl” typically refers to a group having thegeneral formula C_(n)H²⁻¹ and is derived from a cycloalkane by removalof a hydrogen atom from a ring (e.g., a univalent radical such ascyclohexyl, cyclobutyl, cyclopentyl, cycloheptyl, and cyclooctyl formedby removal of one hydrogen atom from a cycloalkane). Typically, acycloalkyl will have between three to 15 carbon atoms, e.g., three—10carbon atoms.

As used herein, “cycloalkylalkyl” typically refers to an alkyl radicalwhich is substituted by a cycloalkyl radical containing from˜three-˜eight (e.g., three-six) carbon atoms.

In aspects, alkyl groups and other referenced groups described hereincan be optionally substituted with one or more substituents. An alkylgroup or other substituted group can be, e.g., mono-substituted (havingonly one substituent), or 1-2 substituents, or 1-3 substituents, or 1-4substituents, etc. The substituents can be selected from the groupconsisting of hydroxy, amino, alkylamino, boronyl, carboxy, nitro,thiol, and the like. When an alkyl group incorporates one or moreheteroatoms, the alkyl group is referred to herein as a “heteroalkyl”group. Similar modifications apply to other optionally substitutedgroups described herein, which can be similarly described using “hetero”terminology (e.g., a heteroaryl group being an aryl group comprising oneor more non-carbon atoms in an aromatic backbone, such as an imidazoleconjugate). As noted elsewhere herein in some cases substituents areadded to a backbone of a compound, are bound to a backbone of acompound, or a hetero-compound comprises both substituents in thebackbone and bound to the backbone of a compound.

As used herein, terms like “heterocyclyl” or sometimes called a“heterocyclic ring” typically refers to any univalent radical derivedfrom a heterocycle by removal of an atom of hydrogen from any ring atom.For the purpose of group definition only, examples of heterocyclylradicals include but are not limited to dioxolanyl,decahydroisoquinolyl, imidazolinyl, piperidinyl, pyrrolidinyl, andthiazolidinyl)

As used herein, the term “heterocyclylalkyl” typically refers to aradical of the formula R_(a)R_(e), where R_(a) is an alkyl radical andR_(e) is a heterocyclyl radical, and if the heterocyclyl is anitrogen-containing heterocyclyl, the heterocyclyl can be attached tothe alkyl radical at the nitrogen atom.

As noted above, as used herein, terms such as “heteroaryl” refers to anaromatic ring (e.g., a ring of 5 or 6 members) wherein the ring isaromatic and has at least one non-carbon constituent. With respect tothese compounds, in some facets, any one or more of positions R⁴, R⁶,R⁸, and R⁹ are —NH₂. In certain alternative facets, any one or more ofpositions R⁴, R⁶, R⁸, and R⁹ comprise a substitution made with a memberof a group selected from the group comprising a/an optionallysubstituted alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl,heteroalkyl, heterocyclyl, heterocyclylalkyl, heteroaryl, orheteroarylalkyl.

According to some aspects, position R² is —Me—OH. According to somealternative aspects, position R² is substituted with a group selectedfrom the group comprising a/an aryl, aralkyl, cycloalkyl,cycloalkylalkyl, heterocyclyl, heterocyclylalkyl, heteroaryl, orheteroarylalkyl.

According to certain facets, any one or more of positions R³, R⁵, R⁷ andR¹⁰ is —OH. In certain alternative facets, any one or more of R³, R⁵, R⁷and R¹⁰ is substituted with a group selected from the group comprisinga/an aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heterocyclyl,heterocyclylalkyl, heteroaryl, or heteroarylalkyl.

In some specific embodiments of the invention, the compound is anycompound described above wherein no more than three, such as for exampleno more than five, no more than three, no more than two, or no more thanone of positions R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, and R¹⁰ differ incomposition from the corresponding position in tobramycin.

In aspects, the compounds of the invention or compounds that arecombined with a complexing agent or functional formulation of theinvention comprise a structure according to the formula below:

wherein R¹-R⁸ are as described in the following paragraph (Formula II).

In some facets, such compounds comprise no more than four, such as nomore than three, no more than two, or no more than one variation(s) atposition(s) R¹, R², R³, R⁴, R⁵, R⁶, R⁷, and R⁸ with respect tocorresponding position(s) in tobramycin (e.g., no more than threepositions R¹-R⁸ vary from corresponding positions in tobramycin). Inaspects, any one or more of R¹-R⁸ of such compounds correspond to theR¹-R⁸ groups of Formula I. In aspects, the groups at positions R², R⁷,or both R² and R⁷ are the same as those in the corresponding positionsin tobramycin. In aspects of such an embodiment, R² is a —Me—Oh and R⁷is an —OH; that is, these positions have the same composition as thecorresponding positions in tobramycin.

According to certain aspects, the compounds of the invention orcompounds that are combined with a functional formulation or complexingagent to achieve improved permeation or retention properties have astructure according to the formula below:

wherein R groups are as described in the following paragraph (FormulaIII).

In certain aspects, any R group of such compounds (R² or R⁸) can be thesame as corresponding R groups described in Formula I, Formula II, orboth Formula I and Formula II. In certain facets, any R group of suchcompounds (R² or R⁸ as shown) that differs from tobramycin can includean optionally derivatized 2-20 (e.g., 2-20, 2-16, 2-12, 2-8, 2-4, or forexample 6-20, 10-20, 14-20, or 18-20, atom backbone alkyl or heteroalkylgroup. In one aspect, the group is a heteroalkyl group. The term“backbone” in this and other contexts of the disclosure will beunderstood as referring to a continuous chain of atoms to which eitherhydrogens or other atoms or groups can be bound. Such an alkyl orheteroalkyl group can be attached by any chemically appropriate bond. Incertain aspects, such a group is attached through an ester or amide bondat a position corresponding to an —OH or —NH₂ group in tobramycin.According to some aspects, the alkyl or heteroalkyl group primarilycomprises, generally consists of, or consists of a linear alkyl orheteroalkyl compound. Such a linear alkyl or heteroalkyl compound can beany suitable linear alkyl or heteroalkyl compound which ispharmaceutically acceptable, ophthalmologically safe, preferablycomprises an amphoteric, lipophilic, or both amphoteric and lipophilicnature, is capable of maintaining stability, and does not negativelyalter the trans-corneal mobility or uptake/retention of the compound orits antibiotic properties. In certain aspects, such a linear alkyl orheteroalkyl compound detectably enhances, e.g., measurably increases,such as statistically improves, the corneal permeation,retention/uptake, or both the corneal permeation and retention/uptake ofthe compound. In certain aspects, the group generally consists of afatty acid or fatty acid derivative that is conjugated to the corestructure of the compound. According to some aspects, such a fatty acid,short fatty acid, or derivative of a fatty acid or short fatty acid canbe any fatty acid suitable according to the characteristics previouslydescribed. In certain aspects, the fatty acid is acetic acid. In certainalternative aspects, the fatty acid is a derivative of acetic acid. Inaspects, the fatty acid is palmitic acid. In certain alternativeaspects, the fatty acid is a derivative of palmitic acid.

According to certain aspects wherein the alkyl or heteroalkyl grouppreviously described is a linear alkyl or heteroalkyl compound, theheteroalkyl group can further comprise one or more (e.g., 1-20, 5-20,10-20, 15-20, 1-15, 1-10, or 1-5) —C═O or NH₂ derivative groups bound tothe group's backbone. In certain alternative aspects wherein the alkylor heteroalkyl group previously described is a linear alkyl orheteroalkyl compound, in some aspects, the group comprises no —C═Ogroups. According to some facets, the group comprises at least two —NH₂groups bound to the backbone, such as at least two, at least three, orsometimes more. In some further aspects, the backbone of the group is aheteroalkyl structure comprising at least one (e.g., at least one, atleast two, or at least three, or sometimes more) nitrogen(s), at leastone (e.g., at least one, at least two, or at least three, or sometimesmore) thiol/sulfur(s), or both. In some facets, at least ˜80%, at least˜85%, at least ˜90% of the atoms of the backbone are carbons. Forexample, in some facets at least ˜90%, or at least ˜95%, or in somecases all the atoms of the backbone are carbons. According to somefacets, the backbone comprises or is bound to an optionally derivatized3-9-membered cycloalkyl, heterocycloalkyl, or heteroaryl ring, such asfor example a 3-8 membered, 3-7 membered, or a 3-6 membered ring. Inaspects, the ring can comprise one or more nitro groups, is bound to oneor more nitro groups, or is bound to one or more side chains bound toone or more nitro groups, such as at least one, at least two, at leastthree, or sometimes more nitro groups. According to some facets, thegroup comprises a single (e.g., only one) ring. Examples ofheterocyclic/heteroaryl rings that can be R groups or that can be boundto a group, such as an optionally substituted alkyl group (or beencompassed in such a group), include, e.g.,

Other, similar derivatizing groups are described in the references citedhere, which are incorporated by reference.

According to some aspects, the compounds described herein are tobramycinderivatives according to Formula I, Formula II, or Formula III. Thus,the term “compound” for example as used in the description of thecompound of Formula I, is intended to encompass any and all acceptabletobramycin derivatives or compounds resulting from the derivatization ofthe compound of Formula I by the substitution of the —OH or —NH₂ groupor a part thereof, e.g., a hydrogen thereof, with an alternativederivatizing/derivative group. In one aspect, at least one derivatizinggroup will be an optionally substituted/derivatized 2-20 atom backbonealkyl or heteroalkyl group as previously discussed. Such derivatizinggroups will include those groups that are pharmaceutically acceptableand ophthalmologically safe and the resulting derivatized molecule willdemonstrate sufficient stability to allow for formulation and delivery,which can be determined by application of routine experimentation giventhe guidance provided herein. Typically, the derivatizing agents alsowill at least substantially maintain the antimicrobial characteristicsof the tobramycin molecule. In aspects the derivatizing group isamphoteric, lipophilic, or both amphoteric and lipophilic. In aspects,one or more derivatizing groups confer a detectable enhancement intrans-corneal penetration, uptake, or retention characteristics ascompared to tobramycin.

In such aspects, a tobramycin derivative can exhibit detectably faster,such as for example at least 2 hours faster, at least 4 hours faster, atleast 6 hours faster, at least 8 hours faster, at least 12 hours faster,at least 16 hours faster, at least 20 hours faster, or, for example atleast 24 hours faster, penetration (e.g., permeation) of corneal cellsthan tobramycin, detectably better retention/uptake (in amount of APItaken up by such cells) in corneal cells than tobramycin, or both. Incertain aspects, a derivatizing/derivative group can have a morelipophilic nature than tobramycin. In certain aspects, thederivatizing/derivative group has a more lipophilic logP than tobramycin(e.g., a logP that is at least ˜10%, at least ˜25%, or at least ˜33%greater than tobramycin). In certain aspects, a derivatized tobramycincompound has a more lipophilic nature than tobramycin and, accordingly,has a more lipophilic logP than tobramycin. In aspects, a derivatizedtobramycin compound can have a lipophilicity similar (e.g., functionallyequivalent) to that of tobramycin and hence a similar logP.

Tobramycin derivatives and derivatizing groups have been described inthe prior art as exemplified in, for example, International PatentPublication WO 2010/132760 (by Dozzo, herein referred to as “Dozzo'760”); Fosso M Y et al, in “Differential Effects of Linkers on theActivity of Amphiphilic Tobramycin Antifungals” (Molecules. 2018;23(4):899. Published 2018 Apr. 13. doi:10.3390/molecules23040899); andFair in the publication titled, “Singly Modified Amikacin and TobramycinDerivatives Show Increased rRNA A-site Binding and Higher Potencyagainst Resistant Bacteria” (ChemMedChem. 2014 September; 9(9):2164-2171. doi:10.1002/cmdc.201402175), and in, for example, the issuedUS patent U.S. Pat. No. 3,872,072 to Naito. Such compounds or compoundscomprising such derivatizing groups can exhibit characteristicsdesirable for use in the invention described in the present application,such as, for example, the ability to exhibit detectably faster (such as,e.g., at least 2 hours faster, at least 4 hours faster, at least 6 hoursfaster, at least 8 hours faster, at least 12 hours faster, at least 16hours faster, at least 20 hours faster, or, e.g., at least 24 hoursfaster) penetration (e.g., permeation) of, and uptake/retention by,corneal cells than tobramycin alone. The provided exemplary artdemonstrates that tobramycin derivatives are known. Hence it should beunderstood that any such pharmaceutically acceptable, ophthalmologicallysafe, amphoteric, and, in aspects, preferably lipophilic derivativesdescribed therein should be understood as being capable of beingincorporated into compositions and methods of the invention described inthis disclosure. The prior art does not, however, appear to describe orsuggest either the limitation of such broad classes of compounds tothose exhibiting the properties described above, complexing suchtobramycin derivatives with a complexing agent to improve the permeationor uptake/retention properties of the API, or formulating the compoundwith/as a liposomal or microsphere formulation to achieve such results,or using any of the above in the particular amounts described herein(e.g., amounts that are significantly less than, such as at least ˜20%,at least ˜25%, at least ˜33%, or at least ˜50% less or more than theamounts of tobramycin used in on-market formulations, such as TOBREX®).

In certain aspects, any one or more substitutions at any one or morelocations described above detectably or significantly enhance, e.g.,measurably improves, such as for example statistically significantlyincreases, the ability of the compound to permeate the cornea or cornealcells, be retained/taken up by the cornea or corneal cells, or bothpermeate and be retained/taken up by the cornea or corneal cells. Suchimprovements are described in more detail below. In certain facets, thederivatizing groups are functional groups such that they enhance thepermeation, retention, and/or permeation, and retention of the compound.According to aspects, the more R-locations of the structures described(e.g., Formula I) wherein substitutions are present, the more thetrans-corneal motility is affected, such as for example when three ormore, four or more, five or more, or even six or more R-locations havesubstitutions, the ability of the compound to permeate the cornea, beretained by the cornea, or both permeate and be retained by the corneaare higher (e.g., exhibit higher availability) than compounds in which asingle, or for example only two R-positions comprise substitutions. Incertain alternative aspects, derivatization does not enhance thetrans-corneal transport rate or corneal retention. That is, thederivatized molecule has substantially the same mobility about thecornea as a non-derivatized molecule. In embodiments, there is a limitto the number of substitutions which confer a motility and hence anavailability benefit, such that, for example, the molecule can reach astate at which no additional substitutions confer a motility orretention benefit or can, in aspects, retard the permeation and/orretention of the compound.

In certain aspects, the concentration of the active derivatized compound(or in aspects tobramycin) within a formulation can be between ˜0.1-˜10%w/v, such as for example between ˜0.1-˜8% w/v, between ˜0.1-6% w/v,between ˜0.1-5% w/v, or between ˜0.1-2.5% w/v, such as for examplebetween ˜0.3-10% w/v, between ˜0.3-8% w/v, between ˜0.3-6% w/v, or forexample between ˜0.3-5% w/v, such as for example between ˜0.1-0.3% w/v,or for example between ˜0.6-10% w/v, between ˜0.6-8% w/v, between˜0.6-6% w/v, or for example between ˜0.6-5% w/v, as in betweenapproximately 1-10% w/v, 1-8% w/v, 1-6% w/v, 1-4% w/v, or 1-3% w/v, forexample approximately 2.5% w/v. Such amounts can also apply totobramycin compositions of the invention that are complexed with acomplexing agent or formulated in functional formulation, such as aliposome or microsphere formulation that enhances the corneal cellpermeability or uptake of tobramycin in a similar manner to complexes ofthe invention.

In aspects, a derivatized compound or tobramycin in a tobramycin complexor functional formulation as described herein can be present in aformulation at a concentration which is at least twice the concentrationof the API in TOBREX®, e.g., at least ˜3 times, ˜4 times, ˜5 times, ˜6times, ˜7 times, ˜8 times, ˜9 times, or at least ˜10 times theconcentration of the API in TOBREX®.

In aspects, derivatization of the compounds of the invention increasesthe rate of cornea cell penetration of the compound. According tocertain aspects, the rate of cornea cell penetration of a derivatizedcompound of the invention can be detectably faster, such as for exampleat least ˜2 hours faster, at least ˜4 hours faster, at least ˜6 hoursfaster, at least ˜8 hours faster, at least ˜12 hours faster, at least˜16 hours faster, at least ˜20 hours faster, or, for example at least˜24 hours faster, than that of tobramycin such that the amount ofcompound in the cornea can be increased by at least ˜15%, such as atleast ˜10%, at least ˜12%, at least ˜15%, at least ˜17%, at least ˜20%,at least ˜22%, or for example at least ˜25% or more after a period of360 minutes from administration of a similar composition comprisingtobramycin.

In aspects, the concentration of a derivatized compound described hereinthat permeates the surface of the cornea can be at least ˜12%, at least˜15%, at least ˜17% greater, such as at least ˜20% greater, such as atleast ˜25% greater, as in at least ˜30% greater, at least ˜35% greater,at least ˜40% greater, as in for example at least ˜45% greater or morethan tobramycin when measured at 360 minutes of an industry standardcorneal permeability assay (e.g., the assay exemplified in the Examplesbelow).

According to certain aspects, the level of retention within the corneaof a derivatized compound of the invention described herein can beretained after 6 hours from administration when measured at 360 minutesas measured by a standard corneal retention assay.

According to some facets, a derivatized compound of the inventiondescribed herein can be retained in at least ˜15% or greater, such as atleast ˜12%, at least ˜15%, at least ˜17%, at least ˜20%, at least ˜22%,or at least ˜25% amount in corneal cells after 15 minutes than acorresponding amount of the API in TOBREX®. In certain aspects, theretention of the compound within the cornea as measured by a standardcorneal retention assay can be at least ˜15% higher, such as at least˜12%, at least ˜15%, at least ˜17% higher, for example at least ˜20%higher, at least ˜25% higher, at least ˜30% higher, or at least ˜32%higher than the retention of tobramycin.

Tobramycin Compound Complexes

Another aspect of the invention relates to a composition comprising acomplex formed by a complexing agent and a tobramycin compound (which iseither tobramycin or a tobramycin derivative). In aspects, thecomplexing agent has an amphoteric nature, a lipophilic nature, or bothan amphoteric and lipophilic nature. In certain facets, the deliveryagents have both a lipophilic and amphiphilic nature and the resultingcomplex molecule also has a measurably increased lipophilic nature ascompared to the API alone. In aspects, the complexing agent is capableof forming a stable complex with the tobramycin compound. In aspects,the complexing agent does not significantly impair the antibioticproperties of the tobramycin compound, does not impair the stability ofthe tobramycin compound, and is ophthalmologically suitable.

The complexing agent detectably improves, in aspects, the ability of thecomplex to permeate corneal cells, be taken up by/retained by cornealcells, or both, as compared to the API alone.

In some facets, the complexing agent can significantly facilitate thereduction of dosing frequency without a significant reduction inefficacy, improve the tolerability, improve patient compliance, reducetreatment duration, increase overall treatment efficacy of thepharmaceutically active compound, such as, for example, in the treatmentof external infections of the eye and its adnexa caused by susceptiblebacteria, or achieve a combination of any or all such effects.

As used herein, the term “complex” is intended to describe molecules orcompounds which are chemically associated with one another but typicallyare not bound together by a covalent bond. For example, a complex cancomprise two molecules or compounds which are bound through ionicbonding, hydrogen bonding, or other suitable types of association thatallow the complex to stably remain associated and to act as a combinedmolecule (at least generally) in the context of a composition or methoddescribed in this disclosure. In aspects, a tobramycin derivativecomprising any parts of the complexes described herein also can becovalently bound, and such covalently bound tobramycin derivative canalso be incorporated in a composition of the invention or used in aninvention.

According to aspects, tobramycin compounds can be complexed to acomplexing agent which is a heterocyclic compound comprising at leastone five-to-seven-member nitrogenous ring comprising an attached chainof at least three carbons and at least one carboxylic acid group. Inaspects, the complexing agent can be an amino acid, such as for exampletryptophan, histidine, or proline. According to aspects, the complexingagent is histidine. In aspects, the complexing agent can be anophthalmologically acceptable derivative of histidine.

Exemplary histidine derivatives suitable for use in the invention hereincan be found in, for example, European patent application EP131631A1(Tanikawa) describing histidine derivatives anserine and carnosine, orin, e.g., the article, “Ophthalmic Pharmacology of N-acetylcarnosineLubricant Eye Drops” by Babizhayev (Mark A. Babizhayev, 2006. OphthalmicPharmacology of N-acetylcarnosine Lubricant Eye Drops. Journal ofPharmacology and Toxicology, 1: 201-233.) The Babizhayev publicationdescribes histidine derivatives N-acetylcarnosine and L-carnosine. It isexpected that at least some of these or other histidine derivativesknown in the art will exhibit properties of a complexing agent in termsof pharmaceutical acceptability, ophthalmological safety, amphotericproperties, or lipophilicity, or also the ability to DOS enhance thepermeation and/or uptake/retention of the complex by corneal cells ascompared to the active pharmaceutical ingredient (API) alone.

In certain alternative aspects, the complexing agent is anophthalmologically safe copolymer. In aspects the ophthalmologicallysafe copolymer can be any copolymer which comprises one or morecharacteristics described above for a suitable complexing agent for usein the invention. In aspects, the complexing agent is Polyvinylcaprolactam-polyvinyl acetate-polyethylene glycol graft co-polymer(PCL-PVAc-PEG).

PCL-PVAc-PEG (structure provided below) originates, interestingly, fromthe need of formulators for a means of preparing solid solutions ofpoorly water-soluble drugs. The BASF polymer Soluplus® is a PCL-PVAc-PEGcomprising significant amphiphilic properties and is one example wellsuited for use in the invention herein. The structure of such a compoundis exemplified here:

Polyvinyl Caprolactam-Polyvinyl Acetate-Polyethylene Glycol GraftCo-Polymer

According to aspects, the complexing agent is a derivative ofPCL-PVAc-PEG. Such derivatives can be any derivative and can compriseone or more characteristics desirable and suitable for incorporationinto the compositions and formulations described herein, such as forexample, pharmaceutical acceptability, ophthalmological safety,amphiphilicity, lipophilicity, and, in some aspects, the ability toenhance the ability of an associated compound to be permeate and/or beretained by the cornea.

In certain aspects, the concentration of the active compound within aformulation can be between ˜0.1-˜10% w/v, such as e.g., between ˜0.1-˜8%w/v, between ˜0.1-6% w/v, between ˜0.1-5% w/v, or between ˜0.1-2.5% w/v,such as, e.g., between ˜0.3-10% w/v, between ˜0.3-8% w/v, between˜0.3-6% w/v, or, e.g., between ˜0.3-5% w/v, such as, for example,between ˜0.1-0.3% w/v, or, e.g., between ˜0.6-10% w/v, between ˜0.6-8%w/v, between ˜0.6-6% w/v, or, e.g., between ˜0.6-5% w/v, as in betweenabout 1-10% w/v, 1-8% w/v, 1-6% w/v, 1-4% w/v, or 1-3% w/v, for example˜2.5% w/v.

In certain aspects, the concentration of the complexing agent within aformulation can be between ˜0.1-˜10% w/v., such as for example between˜0.1-˜8% w/v, between ˜0.1-6% w/v, between ˜0.1-5% w/v, or between˜0.1-2.5% w/v, such as, e.g., between ˜0.3-10% w/v, between ˜0.3-8% w/v,between ˜0.3-6% w/v, or for example between ˜0.3-5% w/v, such as forexample between ˜0.1-0.3% w/v, or for example between ˜0.6-10% w/v,between ˜0.6-8% w/v, between ˜0.6-6% w/v, or, e.g., between ˜0.6-5% w/v,as in between approximately 1-10% w/v, between approximately 1-8% w/v,between approximately 1-6% w/v, between approximately 1-4% w/v, orbetween approximately 1-3% w/v, for example approximately 2.5% w/v.

In some facets, the ratio of complexing agent to API is also ˜0.5:1 to˜2:1 by weight or w/v, such as ˜0.75:1 to ˜1.25:1 w/v, such as ˜0.9:1 to˜1.1:1 w/v or ˜1:1 w/v.

In aspects, a complexed compound can be present in a formulation at aconcentration which is at least twice the concentration of the API inTOBREX®, for example 3 times, at last four times, times, at least sixtimes, at least seven times, at least eight times, at least nine times,or at least ten times the concentration of the API in TOBREX®.

According to some aspects, a compound as described herein, whetherderivatized (e.g., having one or more modifications to an R-group aspreviously described) or non-derivatized (e.g., having no modificationsto an R— group as previously described), complexed with a complexingagent, or formulated in a functional formulation of the invention, canhave a rate of cornea cell permeation that is detectably faster, such asfor example at least ˜two hours faster, at least ˜four hours faster, atleast ˜six hours faster, at least ˜eight hours faster, at least ˜12hours faster, at least ˜16 hours faster, at least ˜20 hours faster, or,for example at least ˜24 hours faster, than the correspondingunmodified/non-complexed compound or formulation. In another aspect, theamount of compound in corneal cells following administration of such aderivative, complex, or functional formulation exhibits an increase ofat least ˜15%, such as at least ˜10%, at least ˜12%, at least ˜15%, atleast ˜17%, at least ˜20%, at least ˜22%, at least ˜25% or more after aperiod of 60 minutes from administration as respectively compared to anunmodified compound, non-complexed compound, or compound in anon-functional formulation. FIG. 5, for example, illustratestobramycin-histidine and tobramycin-polyvinyl caprolactam-polyvinylacetate-polyethylene glycol graft copolymer (Soluplus®) complexes andtheir experimentally derived permeation rates compared to tobramycinalone. This data is further discussed in the Example section herein.

In certain aspects, the concentration of a complexed compound describedherein permeating the surface of the cornea can be at least ˜17%greater, such as for example at least ˜12% greater, at least ˜15%greater, at least ˜17% greater, at least ˜20% greater, at least ˜25%greater, at least ˜30% greater, at least ˜35% greater, or for example atleast ˜40% greater or for example at least ˜45% greater when incomplexed form than in non-complexed form when measured at 360 minutesof an industry standard corneal permeability assay.

In certain aspects, the concentration of a complexed compound permeatingthe surface of the cornea can be at least ˜15% or greater, such as atleast ˜10%, at least ˜12%, at least ˜15%, at least ˜17%, at least ˜20%,at least ˜22%, or at least ˜25% greater or more after 15 minutes fromapplication than a corresponding amount of the API in TOBREX®.

In certain such aspects, the complexing agent is histidine. In certainalternative aspects, the complexing agent is PCL-PVAc-PEG.

According to certain facets, amount of a complexed compound retainedwithin the cornea after ˜6 hours from administration when measured by anindustry standard corneal retention assay is detectably or significantlygreater than the amount of a noncomplexed counterpart compound. Inaspects, the amount of the complex retained is about the same as theamount of the complex compound present in the cornea when the compoundis administered.

In aspects, the retention of a complexed compound of the inventiondescribed herein within the cornea can be at least ˜15% higher, such asat least ˜10%, at least ˜12%, at least ˜15%, at least ˜17%, at least˜20%, at least ˜22%, or at least ˜25% greater or more, such as at least˜30% higher than the retention of the non-complexed compound whenmeasured at 360 minutes as measured by standard corneal retention assay.

According to some aspects, a complexed compound of the invention can beretained in at least ˜15% or greater, such as such as at least ˜10%, atleast ˜12%, at least ˜15%, at least ˜17%, at least ˜20%, at least ˜22%,or at least ˜25% greater or more, amount in corneal cells after 15minutes than a corresponding amount of the API in TOBREX®.

In some such aspects, the complexing agent is histidine. FIG. 6illustrates the experimentally derived retention rates oftobramycin-histidine and tobramycin-polyvinyl caprolactam-polyvinylacetate-polyethylene glycol graft copolymer complexes compared totobramycin alone. This data is further discussed in the Example sectionincluded herein.

In certain aspects, both the concentration of a compound of theinvention permeating the surface of the cornea can be at least about 17%greater, such as for example at least ˜10%, at least ˜12%, at least˜15%, at least ˜17%, at least ˜20%, at least ˜22%, or at least ˜25%greater or more when in complexed form than in non-complexed form whenmeasured at 360 minutes of an industry standard corneal permeabilityassay, and the retention of the complexed compound within the cornea asmeasured by a standard corneal retention assay can be at least ˜25%higher, such as at least ˜10% higher, at least ˜15% higher, at least˜20% higher, or at least ˜30% higher or at least ˜35% higher than theretention of the compound in non-complexed form. In certain aspects, acomplexing agent capable of achieving such a result is, for example, butmay not be limited to, a heterocyclic compound comprising at least one 5to 7-member nitrogenous ring comprising an attached chain of at least 3carbons and at least one carboxylic acid group, such as, for example, anamino acid, e.g., histidine.

Process for Preparing Complexes

According to aspects, complexes discussed herein can be manufactured foruse in larger formulations, e.g., in a solution for administration tothe eye. To form complexes, illustrated here as, e.g.,tobramycin-histidine, solutions according to Tables 1 and 2, below, orsimilar formulations, can be made.

TABLE 1 Tobramycin complexed with histidine. Sr. No IngredientPercentage (w/v) 1 Tobramycin 1.0-10% 2 Histidine 1.0-10% 3 Water q.s.An exemplary manufacturing process for preparing such compositions is asfollows: an amount representing approximately 1-10% of the total batchvolume of tobramycin, and an amount representing approximately 1-10% ofthe total batch volume of histidine are weighed. For example, if a 100mL batch of 2.5% tobramycin-histidine complex solution is desired, 2.5mg of tobramycin and 2.5 mg of histidine are each weighed. The weighedquantities of each tobramycin and histidine are then dissolved in aquantity of water less than the total target batch volume. For example,if a 100 mL batch is being prepared, the weighed tobramycin andhistidine can be dissolved in, for example, approximately 90 mL ofwater. The solution is then brought up to the final target volume withwater. The solution can then be allowed to dry such that the solutionbecomes a dry powder. This can be accomplished by any means; in smallbatch sizes, pouring a small amount of the solution in a series of petridishes can accomplish this quickly. The Examples provided within thisdisclosure demonstrate the efficacy of such a process to form suchcomplexes.

The same process can be followed when preparing, as another example,tobramycin-polyvinyl caprolactam-polyvinyl acetate-polyethylene glycolgraft copolymer complexes. Here, the BASF product Soluplus® is used asthe polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graftcopolymer.

TABLE 2 Tobramycin complexed with Soluplus ®. Sr. No IngredientPercentage (w/v) 1 Tobramycin 1.0-10% 2 Polyvinyl caprolactam-polyvinyl1.0-10% acetate-polyethylene glycol graft copolymer (Soluplus ®) 3 Waterq.s.An amount representing approximately 1-10% of the total batch volume oftobramycin and an amount representing approximately 1-10% of the totalbatch volume of polyvinyl caprolactam-polyvinyl acetate-polyethyleneglycol graft copolymer (Soluplus®) are weighed. For example, if a 100 mLbatch of 2.5% tobramycin-polyvinyl caprolactam-polyvinylacetate-polyethylene glycol graft copolymer (Soluplus®) complex solutionis desired, 2.5 mg of tobramycin and 2.5 mg of polyvinylcaprolactam-polyvinyl acetate-polyethylene glycol graft copolymer(Soluplus®) are each weighed. The weighed quantities of each tobramycinand polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graftcopolymer (Soluplus®) are then dissolved in a quantity of water lessthan the total target batch volume. For example, if a 100 mL batch isbeing prepared, the weighed tobramycin and polyvinylcaprolactam-polyvinyl acetate-polyethylene glycol graft copolymer(Soluplus®) can be dissolved in, for example, approximately 90 mL ofwater. The solution is then brought up to the final target volume withwater. The solution can then be allowed to dry such that the solutionbecomes a dry powder. This can be accomplished by any means known orstandard in the art; in small batch sizes, pouring a small amount of thesolution in a series of petri dishes can accomplish this quickly. TheExamples provided below demonstrate the efficacy of such a process toform such complexes.

According to certain aspects, when utilizing the complex powder toprepare a final formulation, such a final formulation can be sterilizedusing any one or more of the methods selected from heat sterilization,gaseous sterilization, filtration sterilization or radiationsterilization. In common facets, such sterilization means do notdetectably or significantly affect the potency or stability of some,most, or all the compounds of the invention described herein.

Functional Formulations

In certain aspects, other delivery agents that generate a functionalformulation can be used in place of or in addition to complexing agents.A “functional formulation” in this disclosure means a formulation of atobramycin compound (tobramycin or a tobramycin derivative) and one ormore formulating agents, other than a complexing agent, that results ina formulation that exhibits detectably or significantly enhancedpermeation of corneal cells, detectably or significantly enhanced uptakeof API, detectably or significantly enhanced retention of API by cornealcells, or both, and that is ophthalmologically safe and does notsignificantly deter from the API's antibiotic properties. Theformulating agent can be, and the overall formulation can be, morelipophilic than tobramycin. In one aspect, the formulating agentcomprises a liposome having such properties or a microsphere having suchproperties. Out of the numerous types of ophthalmologic formulationsavailable, such formulations can in aspects be particularly capable ofexhibiting such properties.

In one aspect, the functional formulation is a liposome formulation. Inaspects, the liposomes comprise one or more of phosphatidylcholine (PC),cholesterol and one or more of a lipid-conjugated hydrophilicpolymer(s). In aspects, such polymers comprise bioadhesive and/ortrans-corneal permeation-enhancing characteristics. In aspects,liposomes used in the invention are small unilamellar vesicles (SUVs),comprising a single layer of lipid such as lecithin orphosphatidylglycerol encapsulating aqueous interior core. In alternativeaspects, the liposomes used in the invention are multilamellar vesicles(MLVs), comprising various layers of lipid bilayers. In specificaspects, the present liposomes can be small unilamellar vesicles (SUVs),giant unilamellar vesicles (GUVs), and large unilamellar vesicles(LUVs), or any combination thereof.

As exemplified in the 2011 Mishra review publication “RecentApplications of Liposomes in Ophthalmic Drug Delivery” (J Drug Deliv.;2011: 863734), wherein the characteristics of liposomes and theproperties which make them suitable for ophthalmological delivery arewell described, among other publications and patents, multiple liposomalformulations have been investigated and subjects of publication, henceare well known in the art. In aspects, any such liposomes can comprisesuitable characteristics for use in the invention including one or moreof an amphoteric nature, a lipophilic nature, non-interference with thestability of the compound with which they may be present in compositionor formulation, non-interference with the functionality of the active,such as for example, the antimicrobial activity of the accompanyingcompound(s). In addition, such liposomes can detectably enhance theability of the compounds of the invention to permeate, be retained by,or both permeate and be retained by the cornea. Accordingly, suchliposomes should be understood to be suitable for the inclusion withinthe invention described herein and are hereby incorporated by reference.

In another aspect, the functional formulation is a microparticleformulation, such as a nano- or microparticle formulation. In aspects,the functional formulation is a nanoparticle formulation that is adaptedso that an effective amount of the administered nanoparticles is notwashed out of the eye during or following application. In aspects,microparticles or nanoparticles of a formulation comprise, primarilyare, generally are (i.e., generally consist of), substantially are, orentirely are (i.e., consist of) charged microparticles or nanoparticles.In aspects, nanoparticles of a nanoparticle formulation, comprise,primarily comprise, generally consist of, substantially consist of, orconsist of positively charged nanoparticles. In aspects, chargednanoparticles or microparticles of a formulation exhibit DOS improvedaffinity for the cornea than uncharged counterpart particles. Inaspects, microparticles or nanoparticles of a functional formulationprimarily comprise, generally are, substantially are, or consist ofuncharged particles. For example, in an aspect a microparticleformulation is provided that primarily comprises, generally consists of,substantially consists of, or consists of uncharged microparticles.

In facets, a functional formulation is a microparticle formulation,e.g., in the form of microspheres (e.g., is a composition at leastprimarily comprising, generally consisting of, substantially consistingof particles of substantially spherical shape).

In one aspect, a formulation comprises microparticles above onemicrometer in size, such as for example between ˜one micrometer-˜15micrometers, such as between ˜two-˜15 micrometers, such as between˜four-˜15 micrometers, such as between ˜six-˜15 micrometers, such asbetween ˜eight-˜15 micrometers, as in between ˜10-˜15 micrometers, orfor example between ˜one-˜12 micrometers, between ˜one-˜10 micrometers,between ˜one-˜eight micrometers, or for example between ˜one and ˜sixmicrometers. In one aspect, the microparticles comprise, generallyconsist of, or consist of monolithic particles possessing a porous or asolid polymer matrix.

In certain aspects, compounds of the invention can be present in thecore of microspheres in liquid form. In certain aspects, the compoundsof the invention can be present in the core of microspheres in solidform. In alternative aspects, the compounds described herein can beadsorbed onto the surface of a microsphere. According to certainaspects, the particle size of the microspheres utilized herein do notexceed ˜10 micrometers (such as for example no more than ˜10 micrometersin average size in any single direction) so as to avoid ocularirritation which can occur in microsphere formulations comprisingmicrospheres of larger size.

Functional formulations as described above or elsewhere herein can be acomponent of a larger formulation designed for pharmaceutical use intreating, for example, an external infection of the eye or its adnexa.In certain aspects, the formulation can comprise tobramycin and one ormore amphophilic and optionally also lipophilic formulating agents. Incertain facets, the formulating agent comprises liposomes. In certainalternative aspects, the formulation agent comprises microspheres. Incertain aspects, both liposomes and microspheres can be present. Inaspects, the presence of the liposomes, microspheres, or both liposomesand microspheres detectably enhances the permeation of, retention by, orboth permeation of and retention by the cornea (e.g., corneal cells) ofthe tobramycin over a similar formulation comprising tobramycin withoutliposomes or microspheres. In aspects, the tobramycin can be present inthe formulation in a concentration of between ˜0.1-˜10% by weight.

In certain aspects, a formulation for pharmaceutical use in treating,for example, an external infection of the eye or its adnexa can comprisea derivative of tobramycin and one or more amphophilic and optionallyalso lipophilic formulating agents. In certain facets, the formulatingagent comprises liposomes. In certain alternative aspects, theformulation agent comprises microspheres. In certain aspects, bothliposomes and microspheres can be present. In aspects, the presence ofthe liposomes, microspheres, or both liposomes and microspheresdetectably enhance the permeation of, retention by, or both permeationof and retention by the cornea or corneal cells, of the tobramycin, overthat of (compared to) a similar formulation comprising derivatizedtobramycin alone or (formulations not comprising liposomes ormicrospheres). In aspects, tobramycin can be present in a formulation ina concentration of between ˜0.1-˜10% by weight.

According to certain aspects, a formulation for pharmaceutical use intreating, for example, an external infection of the eye or its adnexa,can comprise tobramycin or a tobramycin derivative complexed with acomplexing agent and one or more amphophilic and optionally alsolipophilic formulating agents. In certain facets, the formulating agentcomprises liposomes. In certain alternative aspects, the formulationagent comprises microspheres. In certain aspects, both liposomes andmicrospheres can be present. In aspects, the presence of the liposomes,microspheres, or both liposomes and microspheres detectably orsignificantly enhance the permeation of, retention by, or bothpermeation of and retention by the cornea (e.g., corneal cells) of thetobramycin or tobramycin derivative over that of a similar formulationcomprising non-complexed tobramycin or non-complexed derivatizedtobramycin. In aspects, the tobramycin compound can be present in theformulation in a concentration of between ˜0.1-˜10% by weight (e.g.,˜0.1-0.2% by weight or w/v, ˜0.1-0.3% w/v, ˜0.05%-0.25% w/v, ˜0.6-6%w/v, ˜0.9-3.6% w/v, or ˜1-7.5% or 1-5% w/v). In aspects, the complexingagent can be present in the formulation in a concentration of between˜0.1-˜10% by weight or in any of the other referenced amounts that thetobramycin compound can be present in, +/−˜15%, ˜10%, or ˜5%.

Antimicrobial Activity of Compound/Compositions

Compositions of this invention (compositions comprising tobramycinderivatives, tobramycin compound complexes, and functional formulationsof tobramycin compounds described herein) exhibit anti-bacterialproperties and, accordingly, are useful as antibiotics.

In certain aspects, the compounds of the invention demonstrateantibiotic activity against one or more, in some aspects againstseveral, gram-negative and/or gram-positive ophthalmic pathogens. Incertain aspects, the compounds demonstrate strong activity againstcertain microorganisms, such as specifically for example Staphylococcusaureus and Staphylococcus epidermidis (e.g., both coagulase positive andcoagulase negative S. epidermidis). In certain aspects, the compounds ofthe invention are active against some Streptococci, including some ofthe Group A -beta-hemolytic species, some nonhemolytic species, and someStreptococcus pneumoniae species. In certain facets, the compounds ofthe invention can demonstrate antibiotic activity against suchmicroorganisms as, but not limited to, Pseudomonas aeruginosa,Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes, Proteusmirabillis, Morganella morganii, most Proteus vulgaris strains,Haemophilus influenzae and H. aegyptius, Moraxella lacunata,Acinetobacter calcoaceticus, and some Neisseria species. In certainaspects, the compounds of the invention can demonstrate antimicrobialactivity against penicillin-resistant strains of Staphylococci and alsoantimicrobial activity against microorganisms resistant to gentamicin.

In aspects, formulations comprising tobramycin and at least onecomplexing agent, at least one functional agent (such as liposomes ormicrospheres, or both, which enhance permeability or retention), atleast one complexing agent, and also comprising a derivatized tobramycindemonstrate detectably (measurably) or significantly improvedantimicrobial activity over a similar formulation comprising tobramycinalone (e.g., over that of TOBREX®). E.g., such formulations can in someaspects demonstrate a measurably greater ability (e.g., detectably orsignificantly greater ability) to inhibit bacterial growth as determinedby one or more standard microbial inhibition assays such as, forexample, the Kirby Bauer test.

Stability and Storage

According to certain aspects, the compounds described herein arechemically stable and suitable for pharmaceutical formulation, e.g.,stability is supportive for use in traditional modes and methods ofadministration and traditionally accepted administration schedules.

According to some aspects of the invention, the compounds, compositions,and formulations disclosed herein are stable for extended periods oftime when stored under standard conditions for pharmaceutical activesand, more specifically, for antibiotics in general. The compounds,compositions, and formulations disclosed herein should in aspectsgenerally be stored at between about 2-25° C. (about 36-77° F.) and inaspects should generally be maintained in a safe environment in closedand/or sealed packaging so as to prevent contamination and/ornon-prescribed use.

In some specific aspects, the compounds and compound complexes describedherein retain at least 90% w/w, such as for example at least ˜80%, atleast ˜85%, at least ˜90%, at least ˜92%, at least ˜94%, at least ˜96%,at least ˜98%, or at least ˜99% of the potency of the compound activewhen stored at 25° C. and about 60% relative humidity, or also whenstored at 40° C. and 75% relative humidity for 3 months.

In specific embodiments, a formulation comprising a tobramycin-histidinecomplex, or also a tobramycin-polyvinyl caprolactam-polyvinylacetate-polyethylene glycol graft copolymer complex can in some aspectsmaintain at least about 90% w/w, such as for example at least ˜80%, atleast ˜85%, at least ˜90%, at least ˜92%, at least ˜94%, at least ˜96%,at least ˜98%, at least ˜99% of the potency of tobramycin when stored at25° C. and about 60% relative humidity, or also when stored at 40° C.and 75% relative humidity for 3 months.

Pharmaceutical Formulations

In certain aspects, compositions described herein can be co-administeredwith one or more other agents (e.g., agents alone, agents within acomposition, agents within a formulation, or any combination thereof).As used, herein, compositions of the invention “co-administered” withone or more other actives means the compositions herein are providedseparately from such one or more other agents, such as, e.g., the one ormore other agents are provided in an administration form separate fromthe compositions herein. “Co-administration” can mean two or moreagents, compositions, or formulations administered at the same time asone another, e.g., the two or more agents, compositions, or formulationsare administered together on the same administration schedule (e.g.,three times per day, two times per day, or once per day), or also oralternatively “co-administration” can mean two or more agents,compositions, or formulations administered during the same course oftreatment, e.g., the two or more agents, compositions, or formulationsare administered to a recipient at the same or different times during asingle time period, such as over the course of one day, one week, or onemonth.

In aspects, such a one or more other agents co-administered with thecompositions herein can be any agent which addresses the primaryindication target of the compositions herein, e.g., a microbialinfection such as a bacterial infection of a mammalian eye or itsadnexa, or one or more conditions related to the primary indication,such as, e.g., inflammation (or, e.g., itching, redness, or otherexemplary conditions which can accompany an ocular microbial infection).In aspects, a co-administered agent can be any agent described as asecond active described herein. In aspects, a co-administered agent canbe an antimicrobial agent, e.g., an antibiotic agent. In aspects, aco-administered agent can comprise a compound according to Formula I,Formula II, or Formula III herein. In aspects, a co-administered agentcan be an anti-inflammatory agent, such as an NSAID or a steroid,including any anti-inflammatory agent described herein. In aspects, suchan anti-inflammatory agent can be a dexamethasone compound.

In aspects, compositions described herein can be combined with one ormore other ingredients to form ophthalmologically suitable (e.g.,ophthalmologically useful) formulations, e.g., single formulations, foradministration to a mammalian eye. In aspects, tobramycin derivatives,tobramycin compound complexes, and functional compositions of tobramycincompounds (including tobramycin compound complexes) can be combined withone or more other ingredients to form ophthalmologically usefulformulations for administration to subjects, such as human patients. Ingeneral, such formulations can comprise any suitable type of excipientor other agent, which can include in one aspect one or more additionalAPIs. As various types of formulations will have different properties,however, several groupings of such formulations and types of suchformulations can each represent unique aspects of the invention. Inaspects, such other excipients or APIs can be characterized as being“associated” with a primary compound, e.g., a complexed compound such astobramycin or tobramycin derivative of the compositions describedherein, in that the one or more other excipients or APIs are present ina formulation with a primary compound described herein. In aspects, anexcipient or API associated with a primary compound is delivered withinthe same administration form, e.g., administered concurrently, with theprimary compound.

In aspects, delivery agents that can be associated with a tobramycinderivative or tobramycin compound complex can generally include anypharmaceutically acceptable delivery agent suitable for ophthalmicdelivery such as but not limited to specific emulsifiers to formemulsions, viscosity enhancers such as those used to form ointments,suspending agents, aqueous gels, nanomicelles, nanoparticles,dendrimers, implants, contact lenses, nanosuspensions, microneedles,niosomes, liposomes, microspheres, complexed delivery agents, etc.

In aspects, the compounds of the invention are capable of being added toa pharmaceutical formulation for delivery as a therapeutic drug product.In aspects, such a formulation comprises an effective amount of acompound of the invention, whether in derivatized or non-derivatizedform, along with a complexing agent. In aspects, one or more additionaldelivery agents can be present. The delivery agent could be any deliveryagent described herein. In aspects, the one or more additional deliveryagents can comprise liposomes, microspheres, or both liposomes andmicrospheres. In certain facets, the one or more additional liposome(s),a microsphere(s), or both, are amphoteric. In aspects, the one or moreadditional liposome(s), microsphere(s), or both, are lipophilic. Inaspects, any present delivery agent is suitable for ophthalmologicapplications. In aspects, such formulations provide for the compound tobe retained in at least about 15% greater, such as at least ˜10%, atleast ˜12%, at least ˜15%, at least ˜17%, at least ˜20%, at least ˜22%,or at least ˜25% greater amount in corneal cells after 15 minutes than acorresponding amount of the compound when no additional delivery agentis present.

In aspects, the presence of the one or more additional delivery agentssignificantly enhances the permeation, retention, or both permeation andretention of the compound across and/or within corneal cells compared toa similar formulation comprising no additional delivery agents.

In facets, the formulations of the invention can comprise one or moreexcipients. Such possible excipients are described in detail herein;however, in certain aspects of the invention, one or more excipients canbe selected from a smaller group comprising one or more of aviscosity-enhancer, osmotic modification agent, surfactant, chelatingagent, tonicity agent, buffer, pH-adjusting agent, a preservative, orwater. In aspects, a formulation of the invention can comprise at leastone viscosity enhancing excipient. In aspects, the viscosity enhancingagent can contribute to the viscosity of the formulation. In certainother aspects, the viscosity enhancing agent may not contribute to thefinal formulation viscosity but is present to serve an alternativepurpose and its viscosity enhancing properties, which may be present incertain formulations, is not present in others. In aspects, theviscosity of a formulation of the invention is between about 10 cps andabout 400 cps, such as for example between about 25 cps to about 300cps. In aspects, the viscosity of a formulation comprising a compound incomplex form is at least about 5% higher, such as at least ˜1% higher,at least ˜2% higher, at least ˜3% higher, at least ˜4% higher, at least˜5% higher, at least ˜6% higher, at least ˜7% higher, at least ˜8%higher, at least ˜9% higher, or at least ˜10% higher or more than theviscosity of a similar composition comprising the compound innon-complexed form. In certain aspects, use of a viscosity enhancer canfurther contribute to the viscosity of the formulation beyond thatcontributed by the complexing of the compound with the complexing agent,such as for example the presence of a viscosity enhancing agent canincrease the viscosity of a composition by at least about 1%, at least˜2%, at least ˜3%, at least ˜4%, at least ˜5%, at least ˜6%, at least˜7%, at least ˜8%, at least ˜9%, or at least ˜10% or even higher, suchas at least ˜15%, at least ˜20%, at least ˜30%, at least ˜40%, at least˜50%, at least ˜75%, or even double, triple, or increase the viscosityof a formulation hundreds of times, e.g., 200, 400, 600, or 800 or moretimes over the viscosity of a similar formulation without a viscosityenhancing agent.

According to certain aspects, a pharmaceutical formulation of theinvention can comprise a concentration of a compound described herein ina concentration of between about 0.1-about 10% w/v, such as between˜0.1-˜8% w/v, ˜0.1-˜6% w/v, ˜0.1-˜4% w/v, ˜0.1-˜2% w/v, or ˜0.1-˜1% w/v,such as for example between ˜0.3-˜5% w/v, 0.3-˜4% w/v, ˜0.3-˜2% w/v, or˜0.3-˜1% w/v, as in for example ˜0.6-˜5% w/v, ˜0.6-˜4% w/v, ˜0.6-˜2%w/v, or ˜0.6-˜1% w/v, such as for example between ˜1-˜8% w/v, between˜1-˜6% w/v, between ˜1-˜4% w/v, or, e.g., approximately 2.5% w/v.

According to certain aspects, a pharmaceutical formulation of theinvention can comprise a concentration of a complexing agent describedherein in a concentration of between ˜0.1-˜10% w/v, such as between˜0.1-˜8% w/v, ˜0.1-˜6% w/v, ˜0.1-˜4% w/v, ˜0.1-˜2% w/v, or ˜0.1-˜1% w/v,such as for example between ˜0.3-˜5% w/v, 0.3-˜4% w/v, ˜0.3-˜2% w/v, or˜0.3-˜1% w/v, as in for example ˜0.6-˜5% w/v, 0.6-˜4% w/v, ˜0.6-˜2% w/v,or ˜0.6-˜1% w/v, such as for example between ˜1-˜8% w/v, between ˜1-˜6%w/v, between ˜1-˜4% w/v, or, e.g., approximately 2.5% w/v.

According to certain aspects, tobramycin derivatives, in complexed ornon-complexed forms, are combined with one or more delivery agents orother excipients. In certain aspects, the delivery agent can be anydelivery agent disclosed herein. In some facets, the delivery agent canbe a complexing agent, liposome, or microsphere. In aspects, suchformulations provide for the compound to be retained in at least about15% greater, such as at least ˜10%, at least ˜12%, at least ˜15%, atleast ˜17%, at least ˜20%, at least ˜22%, or at least ˜25% greateramount in corneal cells after 15 minutes than a corresponding amount ofthe compound when no additional delivery agent is present.

According to certain aspects, the presence of the one or more deliveryagents detectably or significantly enhances the permeation, retention,or both permeation of retention of the compound across and/or withincorneal cells compared to a similar formulation comprising no deliveryagents. As discussed above, such formulations are considered “functionalformulations” herein. Such functional formulations can be, e.g., aliposome formulation or a microsphere formulation. Such a functionalformulation can comprise tobramycin, a tobramycin derivative, or amixture of an effective amount of two or more APIs of either such type,in each case in either complexed or non-complexed form.

In certain aspects, a formulation comprising a derivatized ornon-derivatized compound of the invention along with one or moredelivery agents further comprises one or more excipients. Such possibleexcipients are described in detail herein; however, in certain aspectsof the invention, one or more excipients can be selected from a smallergroup comprising one or more of a viscosity-enhancer, osmoticmodification agent, surfactant, chelating agent, tonicity agent, buffer,pH-adjusting agent, a preservative, or water. In certain aspects, aformulation of the invention can comprise at least one viscosityenhancing excipient. In certain aspects, the viscosity enhancing agentcan contribute to the viscosity of the formulation. In certain otheraspects, the viscosity enhancing agent may not contribute to the finalformulation viscosity but is present to serve an alternative purpose andits viscosity enhancing properties, which may be present in certainformulations, is not present in other formulations. In certain aspects,the viscosity of a formulation of the invention is between about 10 cpsand about 400 cps, such as for example between about 25 cps to about 300cps. In aspects, the viscosity of a formulation comprising a derivatizedAPI compound (e.g., a tobramycin derivative) is at least about 5%higher, such as at least about 1% higher, at least about 2% higher, atleast about 3% higher, at least about 4% higher, at least about 5%higher, at least about 6% higher, at least about 7% higher, at leastabout 8% higher, at least about 9% higher or at least about 10% higheror more than the viscosity of a similar composition comprising anon-derivatized API compound (e.g., tobramycin). In certain aspects, theuse of a viscosity enhancing excipient further contributes to theviscosity of a final formulation beyond that contributed by thederivatization of the compound, such as for example the presence of aviscosity enhancing agent can increase the viscosity of a composition byat least about 1%, at least ˜2%, at least ˜3%, at least ˜4%, at least˜5%, at least ˜6%, at least ˜7%, at least ˜8%, at least ˜9%, or at least˜10% or even higher, such as at least ˜15%, at least ˜20%, at least˜30%, at least ˜40%, at least ˜50%, at least ˜75%, or even double,triple, or increase the viscosity of a formulation hundreds of times,e.g., ˜200, ˜400, ˜600, or ˜800 or more times over the viscosity of asimilar formulation without a viscosity enhancing agent.

According to certain aspects, a pharmaceutical formulation of theinvention can comprise a concentration of a derivatized compounddescribed herein in a concentration of between about 0.1-about 10% w/v,such as between ˜0.1-˜8% w/v, ˜0.1-˜6% w/v, ˜0.1-˜4% w/v, ˜0.1-˜2% w/v,or ˜0.1-˜1% w/v, such as for example between ˜0.3-˜5% w/v, 0.3-˜4% w/v,˜0.3-˜2% w/v, or ˜0.3-˜1% w/v, as in for example ˜0.6-˜5% w/v, 0.6-˜4%w/v, ˜0.6-˜2% w/v, or ˜0.6-˜1% w/v, such as for example between ˜1-˜8%w/v, between ˜1-˜6% w/v, between ˜1-˜4% w/v, or for exampleapproximately 2.5% w/v.

In aspects, the one or more additional delivery agents that can becombined with a tobramycin derivative or tobramycin compound complex cancomprise liposomes, microspheres, or both liposomes and microspheres,even where such delivery agents do not result in a functionalformulation. In certain facets, the one or more additional liposome(s),a microsphere(s), or both, are amphoteric. In certain aspects, the oneor more additional liposome(s), microsphere(s), or both, are lipophilic.In aspects, any present delivery agent is suitable for ophthalmologicapplications.

In aspects, formulations comprising liposomes, microspheres, or bothliposomes and microspheres are functional formulations. Suchformulations can provide for the compound to be, e.g., retained/taken upby in at least about 15% greater, such as at least ˜10%, at least ˜12%,at least ˜15%, at least ˜17%, at least ˜20%, at least ˜22%, or at least˜25% greater, amount in corneal cells after 15 minutes than acorresponding amount of the compound when the functional formulation isnot combined with the API. In aspects, such functional formulationscomprising a delivery agent conferring such functionality also providefor the compound to be retained in at least ˜15%, such as for example atleast ˜10%, at least ˜12%, at least ˜15%, at least ˜17%, at least ˜20%,at least ˜22%, or at least ˜25% greater amount in corneal cells after 15minutes than a corresponding amount of the compound when no suchdelivery agent is present.

According to certain facets, the formulations described in this sectioncan comprise one or more excipients. Such possible excipients aredescribed in detail herein; however, in certain aspects of theinvention, one or more excipients can be selected from a smaller groupcomprising one or more of a viscosity-enhancer, osmotic modificationagent, surfactant, chelating agent, tonicity agent, buffer, pH-adjustingagent, a preservative, or water. In certain aspects, a formulation ofthe invention can comprise at least one viscosity enhancing excipient.In certain aspects, the viscosity enhancing agent can contribute to theviscosity of the formulation. In certain other aspects, the viscosityenhancing agent may not contribute to the final formulation viscositybut is present to serve an alternative purpose and its viscosityenhancing properties, which may be present in certain formulations, isnot present in other formulations. In certain aspects, the viscosity ofa formulation of the invention is between about 10 cps and about 400cps, such as for example between about 25 cps to about 300 cps. Inaspects, the viscosity of a formulation comprising liposomes ormicrospheres is at least about 5%, such as at least ˜1% higher, at least˜2% higher, at least ˜3% higher, at least ˜4% higher, at least ˜5%higher, at least ˜6% higher, at least ˜7% higher, at least ˜8% higher,at least ˜9% higher, or at least ˜10% higher or more than the viscosityof a similar composition comprising the compound without the presence ofliposomes or microspheres. In certain aspects, the use of a viscosityenhancing excipient further increases the viscosity of the formulation,such as for example the presence of a viscosity enhancing agent canincrease the viscosity of a composition by at least ˜1%, at least ˜2%,at least ˜3%, at least ˜4%, at least ˜5%, at least ˜6%, at least ˜7%, atleast ˜8%, at least ˜9%, or at least ˜10% or even higher, such as atleast ˜15%, at least ˜20%, at least ˜30%, at least ˜40%, at least ˜50%,at least ˜75%, or even double, triple, or increase the viscosity of aformulation hundreds of times, e.g., ˜200, ˜400, ˜600, or ˜800 or moretimes over the viscosity of a similar formulation without a viscosityenhancing agent.

According to certain aspects, a pharmaceutical formulation of theinvention can comprise a concentration of a compound described herein ina concentration of between about 0.1-about 10% w/v, such as between˜0.1-˜8% w/v, ˜0.1-˜6% w/v, ˜0.1-˜4% w/v, ˜0.1-˜2% w/v, or ˜0.1-˜1% w/v,such as for example between ˜0.3-˜5% w/v, 0.3-˜4% w/v, ˜0.3-˜2% w/v, or˜0.3-˜1% w/v, as in for example ˜0.6-˜5% w/v, 0.6-˜4% w/v, ˜0.6-˜2% w/v,or ˜0.6-˜1% w/v, such as for example between ˜1-˜8% w/v, between ˜1-˜6%w/v, between ˜1-˜4% w/v, or for example approximately 2.5% w/v.

According to certain aspects, a pharmaceutical formulation of theinvention can comprise a concentration of a complexing agent describedherein in a concentration of between about 0.1-about 10% w/v, such asbetween ˜0.1-˜8% w/v, ˜0.1-˜6% w/v, ˜0.1-˜4% w/v, ˜0.1-˜2% w/v, or˜0.1-˜1% w/v, such as for example between ˜0.3-˜5% w/v, 0.3-˜4% w/v,˜0.3-˜2% w/v, or ˜0.3-˜1% w/v, as in for example ˜0.6-˜5% w/v, 0.6-˜4%w/v, ˜0.6-˜2% w/v, or ˜0.6-˜1% w/v, such as for example between ˜1-˜8%w/v, between ˜1-˜6% w/v, between ˜1-˜4% w/v, or for exampleapproximately 2.5% w/v.

In aspects, excipients that can be incorporated into formulations of theinvention can comprise any suitable excipient such as those commonlyused in pharmaceutical formulation development, e.g., those used forstability, preservation, pH control and the like. In certain commonaspects, one or more pharmaceutically acceptable excipients used in theophthalmic compositions include but are not limited to a thickeningagent or viscosity-enhancer, solubilizers, penetration enhancers,chelating agents, tonicity agents, buffers or pH-adjusting agents,preservatives, and water.

In aspects, the solubilizer and the penetration enhancer are the samecomponent (e.g., the same compound serves both to solubilize and enhancepenetration). In alternative aspects, separate compounds can serve eachfunction. Exemplary solubilizers and penetration enhancers include, butare not limited to, polysorbate 80, tocopherol polyethylene glycolsuccinate (TPGS), polyoxyl 35 castor oil, polyarginine, polyserine,tromethamine (tris), and sesame seed oil. The solubilizer and thepenetration enhancer can be present is in an amount of about 0.5% to 2%by weight, such as for example ˜0.1-˜5% by weight, ˜0.2-4% by weight,˜0.3-˜3% by weight, or for example ˜0.5-˜2% by weight.

In aspects, viscosity-enhancing agents are used in the ophthalmiccompositions to improve the form of the formulation for convenientadministration and to improve contact with the eye and thereby improveavailability and/or bioavailability. Exemplary thickening agents includepolymers containing hydrophilic groups such as monosaccharides andpolysaccharides, ethylene oxide groups, hydroxyl groups, carboxylicacids, or other charged functional groups. While not intending to limitthe scope of the invention, in aspects viscosity-enhancing agents suchas hydroxypropyl methylcellulose (HPMC), sodium carboxymethylcellulose,povidone, polyvinyl alcohol, and polyethylene glycol can be used.

High viscosity forms of ophthalmological formulations and the agents forachieving the same are known. TOBREX®, discussed in the background ofthe present disclosure, is available in two forms, one being a (drop)form and the other being an ointment, ointments being a commonformulation strategy for improving ocular drug delivery well known inthe art. A key to topical ophthalmological active efficacy is theability to maintain contact with the surface of the eye which is impededby the eyes natural defense mechanism which include such things asnasolacrimal flushing. The eye can be more successful at flushingthinner solutions than thicker, more viscous solutions, hence many inthe art have sought to improve ophthalmologic drug delivery usingviscosity enhancers. Methylcellulose, hydroxy methyl cellulose, hydroxyethyl cellulose, sodium carboxy methyl cellulose, hydroxypropyl methylcellulose, polyalcohol, e.g., polyvinyl alcohol, andpolyvinylpyrrolidone are just a few examples of commonly used viscosityenhancers. International Patent Publication Number PCT/US2010/039618(Kabra) is an example of existing art wherein xanthan gum is describedas a viscosity enhancing agent. The Kernt, European Journal ofOphthalmology publication referenced in the background section of thisapplication also discloses viscosity-enhanced solutions (e.g., viscosityenhanced solutions of 0.3% tobramycin). Such art demonstrates thatviscosity enhancement is known and as some of the viscosity enhancers ofthe prior art can be suitable for the formulations described herein(e.g., they are pharmacologically acceptable and ophthalmologically safeand do not cause interference with the eye); in aspects, such viscosityenhancers can be accordingly incorporated into formulations describedhere.

In aspects, viscosity-enhancing agents can be present from about 0.1% toabout 2% by weight, such as for example 0.1-˜5% by weight, about 0.2-4%by weight, ˜0.3-˜3% by weight, or for example about 0.5-˜2% by weight.According to certain aspects, the viscosity enhancer can increase theviscosity of the formulation from about 1 to about 700 cps at a shearrate of 6 sec-1 and a temperature of 25° C.

In aspects, tonicity agents are used in the ophthalmic compositions toadjust the composition of the formulation to be within a desiredisotonic range. Examples thereof include ionic isotonic agents,non-ionic isotonic agents, and the like. Examples of the ionic isotonicagents include inorganic salts and organic salts. Examples of theinorganic salts include sodium chloride, disodium phosphate, sodiumdihydrogen phosphate, potassium dihydrogen phosphate, sodium hydrogensulfite, sodium sulfite, sodium thiosulfate, magnesium sulfate,potassium chloride, calcium chloride, magnesium chloride, boric acid,borax, and the like. Examples of the organic salts include potassiumacetate, sodium acetate, sodium hydrogen carbonate, sodium carbonate,and the like. Examples of the non-ionic isotonic agents includepolyhydric alcohols having two or more alcoholic hydroxy groups insingle molecules, and the like. Specific examples of the polyhydricalcohols include, for example, glycerol, propylene glycol, polyethyleneglycol, glucose, trehalose, mannitol, dextrose, sucrose, xylitol,sorbitol, and the like.

In certain aspects, formulations of the invention can comprise one ormore such tonicity agents. In aspects, one or more tonicity agents arepresent in a formulation in the amount of about 0.01% to 0.8% by weight,such as between ˜0.01-˜0.8% by weight, between ˜0.01-˜0.6% by weight,between ˜0.01-˜0.4% by weight, between ˜0.01-˜0.2% by weight, or between˜0.01-˜0.1% by weight, as in for example between ˜0.05-˜0.8% by weight,0.1-˜0.7% by weight, 0.2-˜0.6% by weight, or for example between˜0.3-0.5% by weight. In certain aspects, among these isotonic agents,the non-ionic isotonic agents are preferably polyhydric alcohols such asglycerin, propylene glycol, and polyethylene glycol; the ionic isotonicagents can in aspects preferably be inorganic salts such as boric acidand borax; in aspects glycerin and borax can be ore preferable; inaspects, one such agent can comprise or be glycerin.

According to certain aspects, the formulations described herein can havean osmolality of about 250 to about 350 mOsm/kg, such as ˜200-˜500mOsm/kg, for example ˜200-˜400 mOsm/kg, ˜200-˜300 mOsm/kg, or forexample ˜300-˜500 mOsm/kg. In aspects, the isotonic agents in theinvention can be used alone, or two or more thereof can be used in anycombination. In certain aspects, one tonicity agent is used. In certainaspects, more than one tonicity agents are used.

Chelating agents are used in ophthalmic compositions to enhancepreservative effectiveness by forming stable water-soluble complexes(chelates) with alkaline earth and heavy metal ions. Exemplary chelatingagents include, but are not limited to, ethylenediaminetetraacetic acid(EDTA), or salts thereof. In aspects, any one or more chelating agentsare present in the formulation. In a typical aspect, the chelating agentis present in an amount from about 0.001-about 0.1% by weight, such asbetween ˜0.005-˜0.05% by weight, between ˜0.01-˜0.04% by weight, ore.g., between ˜0.001-˜0.05% by weight, or for example between ˜0.05% and˜0.1% by weight.

Buffers or pH-adjusting agents in the ophthalmic compositions are usedto adjust the pH to a desirable range. Exemplary buffers include, butare not limited to, phosphate buffer, citrate buffer, tris buffer,carbonate buffer, succinate buffer, maleate buffer and borate bufferalone or in combination thereof. According to certain aspects, the pH ofthe present solutions, compositions, and formulations described hereinshould be maintained within a pH range of 6.0 to 9.0. The amounts ofbuffers used in the composition ranges to aid in such pH maintenancecan, in some aspects, range from between about 0.05% to about 2.5% byweight, such as for example between ˜0.05%-˜2% by weight, 0.05%-˜1.5% byweight, or between ˜0.05%-˜1% by weight, or for example between˜0.1%-˜20.5% by weight, between ˜0.5%-˜20.5% by weight, or between˜1%-˜20.5% by weight.

Preservatives in the ophthalmic compositions are used to inhibitmicrobial growth. In aspects, suitable nontoxic preservatives include,but are not limited to zinc chloride, sodium chlorite, sodiumhydroxymethyl glycinate, polyquaternium compound such aspolyquaternium-1, cationic compounds such as chlorhexidine gluconate,p-hydroxybenzoates such as methyl p-hydroxybenzoate, ethylp-hydroxybenzoate, propyl p-hydroxybenzoate and butyl p hydroxybenzoate,alcohol compounds such as phenylethyl alcohol, benzyl alcohol andchlorobutanol, sodium dehydroacetate; amino acids such as cysteine andmethionine, citric acid and sodium citrate and other preservatives suchas thimerosal, octadecyldimethylbenzyl ammonium chloride, hexamethoniumchloride, benzethonium chloride, phenol, catechol, resorcinol,cyclohexanol, 3-pentanol, m-cresol, phenylmercuric nitrate,phenylmercuric acetate or phenylmercuric borate, sodium perborate andthe like either alone or in combination thereof. In certain aspects, theformulations described herein comprise one or more preservatives. Inaspects, the amount of preservative used in the composition ranges fromabout 0.005% to about 0.3% by weight, such as ˜0.007-˜0.2% by weight, orfor example between ˜0.01%-˜0.1% by weight.

In aspects, compositions/formulations described herein can comprise oneor more agents which may provide antimicrobial activity beyond thatwhich is provided by the primary active(s), provide preservativefunctionality, serve as a surfactant, or any combination thereof. Inaspects, one or more such compounds can be a quaternary ammoniumcompound, such as benzalkonium chloride. In aspects, a quaternaryammonium compound can be present in a composition/formulation in anamount that detectably or significantly (DOS) extends the preservationof the composition/formulation (e.g., extend shelf life), DOS increasethe antimicrobial activity beyond that of the primary active(s), toeffectively serve as a surfactant, or any combination thereof. Inaspects, compositions/formulations described herein comprise, e.g.,between about 0.01-about 0.2 mg/mL of benzalkonium as a 10% solution,such as between ˜0.02-˜0.19 mg/mL, between ˜0.03-0.18 mg/mL, between˜0.04-0.17 mg/mL, between ˜0.05-0.16 mg/mL, between ˜0.06-0.15 mg/mL,between ˜0.07-0.14 mg/mL, between ˜0.08-0.13 mg/mL, between ˜0.09-0.12mg/mL, or about 0.1 mg/mL of a 10% solution of benzalkonium chloride.According to certain aspects, compositions/formulations described hereincomprise no benzalkonium chloride. That is, in aspects,compositions/formulations can be free of benzalkonium chloride.

According to certain aspects, compositions/formulations described hereincomprise no additional pharmaceutically active ingredients.

In aspects, it can be beneficial to incorporate one or more additionalagents into the compositions and formulations described herein. Forexample, in aspects, compositions described herein can comprise (1) anantibacterial component comprising (a) a complex comprising (i) anactive pharmaceutical ingredient (API) (primary active) wherein theactive pharmaceutical ingredient is tobramycin, a similar compound, or aderivative of either thereof and (ii) a complexing agent, or (b) aderivative of tobramycin or a similar compound comprising one or moreconjugates/derivatizing groups, wherein the complexing agent orconjugate(s) cause a detectable increase in API permeation of cornealcells, retention in corneal cells, or both, as compared to thenon-complexed or non-derivatized API, and (2) an effective amount of oneor more additional active agents, e.g., an anti-inflammatory agent, suchas an NSAID or steroid (e.g., dexamethasone or another dexamethasonecompound).

In aspects, a single composition or a single formulation can comprisecompositions comprising compounds of the invention described herein andcan further comprise one or more additional agents within the samecomposition or formulation (e.g., a combination composition orcombination product) as opposed to such one or more agents beingco-administered as described elsewhere herein. In aspects, such an agentmay not be a pharmaceutically active ingredient. In aspects, such anagent can be a supplement. In aspects, such an agent can be apharmaceutically active ingredient. As used herein, a pharmaceuticallyactive ingredient, or alternatively stated, an active pharmaceuticalingredient (API) is an ingredient which demonstrated biological activityand is regulated by the United States Food and Drug Administration (FDA)for use in the United States. While many ingredients can demonstratebiological activity, some ingredients may not require FDA approval forincorporation into such formulations as ophthalmologic formulations andhence, as used herein, such ingredients are not considered an API. Inaspects, a non-API ingredient can still demonstrate biological activity.In certain aspects, the term “active”, such as an “active” agent, can beany ingredient demonstrating biological activity. In certain aspects,any formulation described herein can further comprise one or moreadditional actives. Such an agent/active can be any pharmaceuticallyacceptable, ophthalmologically safe component which does notsignificantly impede the performance of any one or more other co-presentactives. Any such agent/active, in aspects, is suitable forco-administration with the primary compounds of the compositionsdescribed herein. In aspects, such an additional agent or active can beany agent or active generally supportive of ocular health or supportiveof treating a condition of the eye or its adnexa, such as, e.g., one ormore ophthalmologically suitable forms of an antihistamine (e.g.,ketotifen fumarate, alcaftadine, azelastine, bepotastine, cetirizine,emedastine, epinastine, ketotifen, olopatadine, and the like); adecongestant (e.g., naphazoline, phenylephrine, oxymetazoline,tetrahydrozoline, or the like); one or more ophthalmologically suitablelubrication agents (e.g., agents comprising one or more ingredientscommon in eye lubrication compositions such as but not limited to, e.g.,glycerin, propylene glycol, polyvinyl alcohol, povidone, polyethyleneglycol, dextran, methylcellulose, hydroxypropyl methylcellulose, apolysorbate (e.g., polysorbate 80), petrolatum, mineral oil, lanolin,chlorobutanol, sodium chloride, Hypromellose, phosphoric acid, sodiumhydroxide, sodium perborate, carboxymethylcellulose,polyvinylpyrrolidone, boric acid, potassium chloride, sodium borate,sodium chlorite, sodium hyaluronate, retinyl palmitate, tocopherylacetate, magnesium ascorbyl phosphate, phenoxyethanol, and glyceryl); orone or more ophthalmologically suitable supplements (e.g., but notlimited to an antioxidant such as lutein or zeaxanthin, or a vitaminsuch as, e.g., vitamin A, vitamin C, or vitamin D). In certain aspects,such an active can be a prostaglandin, such as bimatoprost, latanoprost,or other prostaglandin compounds or derivatives of the same. In aspects,such an active can be included which supports the treatment of theindication for which the compounds of the invention are targeted. Thatis, for example, an active can be incorporated which further addressesan ocular infection, such as, for example, one or more additionalantimicrobial agents. Also, one or more additional actives can beincorporated which address one or more conditions related to the primaryindication. As an example, in one aspect, the formulations describedherein can include one or more anti-inflammatory agents, as inflammationoften accompanies infection or, also, can result from the application offoreign material such as a drug treatment to the eye. In aspects, suchan additive can be a non-steroid anti-inflammatory drug (NSAID) (suchas, e.g., bromfenac, indomethacin, diclofenac, flurbiprofen, ketololactremethamine, or nepafenac). In aspects, such an additive can be asteroid or corticosteroid, such as, e.g., difluprednate, fluocinolone,fluorometholone, triamcinolone, rimexolone, prednisolone, medrysone,dexamethasone, or loteprednol (e.g., loteprednol etabonate). In certainaspects, compositions can comprise an anti-inflammatory steroid such asdexamethasone.

In aspects, the concentration of one or more additional actives in acomposition/formulation can be any concentration suitable to achieve atargeted result, such as a sufficient concentration to DOS inhibitgrowth of an infective agent (e.g., if the active exhibits antimicrobialactivity), or e.g., a sufficient concentration to DOS reduce oreliminate inflammation). According to certain aspects, an additionalactive can be an ophthalmologically suitable antimicrobial agent, suchas an antibacterial agent, according to Formula I, Formula II, orFormula III described herein. In aspects, the concentration of such anantimicrobial agent within a composition/formulation can be less than,the same as, or higher than the primary complexed active compound. Inaspects, the concentration of such an antimicrobial agent within acomposition/formulation can be, e.g., between about 0.01-about 10%, suchas between ˜0.01-˜9% w/v, ˜0.01-˜8% w/v, ˜0.01-˜7% w/v, ˜0.01-˜6% w/v,˜0.01-˜5% w/v, ˜0.01-˜4% w/v, ˜0.01-˜3% w/v, ˜0.01-˜2% w/v, ˜0.01-˜1%w/v, such as between about 0.2-about 6% w/v, or between about 0.3-about5% w/v.

According to certain aspects, an additional active can be ananti-inflammatory agent, such as an ophthalmologically suitablenon-steroidal anti-inflammatory (NSAID) agent or a steroid. In aspectsthe agent can be a steroid. In specific aspects, the agent can bedexamethasone or a dexamethasone compound. A “dexamethasone compound” isa compound that is a recognized or known analog of dexamethasone or ananalog having a substantially similar structure and exhibitingsubstantially similar properties as dexamethasone, but excludingsteroids recognized as distinct from dexamethasone in the art, aderivative of dexamethasone or a dexamethasone analog, an alternativeform of dexamethasone (e.g., a salt form other than the commonly useddisodium phosphate form of dexamethasone) or an alternative form of aknown dexamethasone analog or derivative, or a complex comprising anyone or more of such compounds, in any case which exhibits similar orimproved pharmaceutical activity as dexamethasone in the context of theformulations and methods described herein. A dexamethasone compound canin aspects be a stereochemically isomeric form (an isomer) ofdexamethasone or a tautomer of dexamethasone. In aspects, thedexamethasone or other dexamethasone compound can be present in anysuitable form. Examples of dexamethasone analogs and derivatives areknown in the art (see, e.g., Galassi F et al. Br J Ophthalmol. 2006November; 90(11):1414-9. doi: 10.1136/bjo.2006.099838). In aspects, thesteroid content of the formulation comprises dexamethasone, primarilycomprises dexamethasone, consists essentially of dexamethasone, orconsists of dexamethasone. In aspects, compositions herein can compriseone or more other active agents, such one or more other active agentspresent in any suitable form, such as any suitable derivatized form, anysuitable salt form, any suitable isomer form, any suitable tautomericform, or any other derivative thereof. For example, a secondantimicrobial agent can be present in any suitable form such as a salt,or, also or alternatively, an anti-inflammatory agent such as an NSAIDor a steroid can be present in any suitable form, such as a salt. Inaspects, the composition(s) herein comprise(s) a salt of dexamethasoneor a dexamethasone compound, such as a disodium phosphate salt. Inaspects, the dexamethasone or dexamethasone compound is associated witha pharmaceutically acceptable salt other than a disodium phosphate salt.Pharmaceutical salts are known in the art, and, in aspects, alternativesalts can be selected without undue experimentation. Examples ofpharmaceutical salts are well known in the art (see, e.g., Berge,“Pharmaceutical Salts”; Journal of Pharmaceutical Sciences; Volume 66,Issue 1, January 1977; Pages 1-19).

In aspects, the concentration of an anti-inflammatory agent, e.g., anNSAID or steroid, such as, e.g., dexamethasone or a dexamethasonecompound, within a composition can be, e.g., between about 0.01-about 1%w/v, such as between ˜0.01-˜0.9% w/v, between ˜0.01-˜0.8% w/v, between˜0.01-˜0.7% w/v, between ˜0.01-˜0.6% w/v, between ˜0.01-˜0.5% w/v,between ˜0.01-˜0.4% w/v, between ˜0.01-˜0.3% w/v, between ˜0.01-˜0.2%w/v, between ˜0.01-˜0.1% w/v, or for example between about 0.02-about0.3% w/v, such as between ˜ 0.02-˜0.25% w/v, ˜0.02-˜0.2% w/v, or between˜0.02-˜0.15% w/v. In certain aspects, concentrations of ananti-inflammatory agent are the same as that in TOBRADEX® or othersimilar on-market products. In aspects, concentrations of ananti-inflammatory agent are about 1%, ˜2%, ˜3%, ˜4%, ˜5%, ˜6%, ˜7%, ˜8%,˜9%, or about 10% or more less than that in TOBRADEX® or other similaron-market products. For example, in aspects, an anti-inflammatory agentsuch as dexamethasone or another dexamethasone compound is present in aconcentration of between about 0.01-about 1% w/v, such as between˜0.02-˜0.8% w/v, between ˜0.04-˜0.6% w/v, between ˜0.06-˜0.4% w/v,between ˜0.08-˜0.2% w/v, or in a concentration of about 0.1% w/v.

In aspects, compound or compound complexes of the invention can bepresent within a formulation comprising one or more additional activeagents in a ratio of about 50:1, such as ˜45:1, ˜40:1,-35:1, ˜30:1, or˜25:1, such as, e.g., ˜20:1, ˜15:1, ˜10:1, ˜5:1, or even ˜1:1. E.g., inaspects a compound or compound complex of the invention can be presentwithin a formulation comprising an additional antibacterial agent,wherein the ratio of the compound or compound complex of the inventionis present with the antibacterial agent in a ratio of about 0.5:1, ˜1:1,˜1:1.5, or, e.g., ˜1:2 or more. In another example, a compound orcompound complex of the invention can be present within a formulationcomprising an anti-inflammatory agent, wherein the ratio of the compoundor compound complex of the invention is present within theanti-inflammatory agent in a ratio of about 40:1, e.g., ˜35:1, ˜30:1,˜25:1, or, e.g., ˜20:1. In one specific example, the invention is aformulation comprising ˜2.5% w/v of a compound or compound complexdescribed herein and ˜0.1% w/v dexamethasone or dexamethasone compound,e.g., dexamethasone.

In a specific aspect, compositions of the invention can comprise (1) anophthalmologically suitable complex, the complex comprising (a) anantimicrobial active pharmaceutical ingredient comprising an effectiveamount of a compound having a structure according to Formula I and (b)an ophthalmologically suitable lipophilic and amphoteric complexingagent, which forms a complex with the active pharmaceutical ingredient,and (2) a pharmaceutically effective amount of dexamethasone or anotherdexamethasone compound, wherein the complexing agent detectably promotesthe uptake of the active pharmaceutical ingredient by corneal cells, theretention of the active pharmaceutical ingredient by corneal cells, orboth, as compared to the free (non-complexed) active pharmaceuticalingredient alone. In aspects, the compound is tobramycin, the complexingagent is histidine, and the composition comprises dexamethasone.

Within the formulations described herein comprising a complexing agent,such complexes can be amenable for the replacement of the compoundsdescribed herein with other water soluble or hydrophobic active agents.In aspects, such other actives can be added to a formulation asdescribed herein, such as for example to a formulation comprising one ormore complexed compounds, one or more derivatized compounds, and eitherof such formulations with or without an additional delivery agent.

In one aspect, an additional additive can be complexed with a deliveryagent as described herein. In an alternative aspect, such actives can bedelivered by the presence of one or more delivery agents, such as aliposome or a microsphere. Hence, in certain aspects, the formulationspreviously described can also comprise one or more additional actives.The one or more additional actives can, in certain aspects, measurablyenhance the ability of a compound of the invention to permeate, beretained by, or both permeate and be retained by the cornea of the eyewhen used in ophthalmic applications. In alternative aspects, the one ormore additional actives may not significantly impact the ability of acompound of the invention to permeate, be retained by, or both permeateand be retained by the cornea when used in ophthalmic applications. Inaspects, the use of a complexing agent or other delivery agent such asliposomes or microspheres can be used to delivery any of the activesdisclosed herein in the absence of any of the compounds disclosed as anaspect of the invention.

In aspects, one or more other active agents can be beneficial for thetreatment of an ocular condition. In certain aspects, such other activescan include but not be limited to i) anti-glaucoma drugs, such as thebeta-blockers, e.g., timolol maleate, betaxolol, carteolol andmetipranolol; epinephrine and prodrugs; such as dipivefrin; carbonicanhydrase inhibitors; such as dorzolamide, brinzolamide, acetazolamide,dichlorphenamide and methazolamide; dopaminergics, prostaglandins,docosanoids, alpha-2 agonists; angiotensin II antagonists; alpha-Iantagonists; cannabinoids; endothelin antagonists; ii) miotics, e.g.,pilocarpine, acetylcholine chloride, isoflurophate, demecarium bromide,echothiophate iodide, phospholine iodide, carbachol, and physostigmine;iii) drugs for treatment of macular degeneration, such as interferon,particularly α-interferon; transforming growth factor (TGF), e.g. TGF-P;iv) anti-cataract and anti-proliferative diabetic retinopathy (PDR)drugs, such as aldose reductase inhibitors: e.g. tolrestat, orangiotensin-converting enzyme inhibitors, e.g. lisinopril, enalapril; v)drugs for treatment of age-related exudative macular degeneration (AMD),e.g. ocular neovascular disease, such as staurosporines, phthalazinederivatives; vi) anti-clotting agents, such as tissue plasminogenactivator, urokinase, and streptokinase; vii) drugs for treatment ofocular inflammatory diseases such as cortico-steroids; e.g.prednisolone, triamcinolone, dexamethasone, fluocinolone, cortisone,prednisolone, fluorometholone and the like, non-steroidalanti-inflammatory drugs, such as ketorolac tromethamine, didofenacsodium, indomethacin, flurbiprofen sodium, and suprofen; viii)antibiotics, such as cephaloridin, chloramphenicol, clindamycin,amikacin, gentamicin, methicillin, lincomycin, oxaciilin, penicillin,amphotericin B, polymyxin B, cephalosporin family, ampicillin,bacitracin, carbenicillin, cefalotin, colistin, erythromycin,streptomycin, neomycin, sulfacetamide, vancomycin, silver nitrate,sulfisoxazole diolamine, quinolones, and tetracycline; ix) anti-fungalor anti-viral agents, such as miconazole, ketoconazole, idoxuridine,trifluridine, vidarabine, acyclovir, gancyclovir, foscarnet sodium,cidofovir, valacyclovir, famciclovirtrisulfapyrimidine-2, nystatin,flucytosine, natamycin, aromatic diamidines e.g. dihydroxystilbamidineand piperazine derivatives, e.g. diethylcarbamazine; x) cycloplegics andmydriatic agents, such as atropine, cyclopentolate, scopolamine,homatropine tropicamide and phenylephrine; xi) drugs for the treatmentof ocular neurodegenerative diseases such as isopropyl unoprostone,glutamate receptor antagonists, e.g. memantine, caspase inhibitors,calcium antagonists, sodium channel blockers, NOS-2 inhibitors orneurotrophic factors, e.g. glial derived neurotrophic factor (GDNF) orciliary neurotrophic factor (CNTF); xii) peptide drugs such ascalcitonin, lypressin or a somatostatin or analogues thereof, xiii)anti-VEGF drugs; xiv) phosphodiesterase inhibitors; xv) antisense drugssuch as fomivirsen sodium; xvi) immunosuppressive agents; such asazathioprine, cyclosporin A, methotrexate, colchicine; xvii) drugs forthe treatment of ocular angiogenesis such as angiostatic steroids, PKCinhibitors, VEGF antagonists, COX2 inhibitors, ACE inhibitors orangiotensin II antagonists; xviii) free radical scavengers, e.g. alphatocopherol, carotenoids, sulfhydryl-containing compounds.

According to some aspects, the formulations of the invention can bedelivered in any matrix suitable for the target condition. In certainaspects, the formulations described herein can be utilized to treat anon-ocular condition such as an infection of the skin, wherein a topicalcream or ointment is a suitable method of administration. In certaincommon aspects, the formulations are developed for application to theeye. In aspects, matrices suitable for delivering active pharmaceuticalagents to the eye include but may not be limited to ointments,solutions, emulsions, dispersions, and suspension.

In one aspect, formulations described herein can be delivered as asolution. In one embodiment, the formulations are delivered as asolution via drops administered to the eye. In certain alternativeembodiments, the formulation is delivered as an ointment, wherein astrip of ointment is applied to the afflicted eye. As used herein, adescription of a “drop” of a solution/formulation to the eye describes adrop size common in the art for ocular formulations designed to bedelivered by liquid drop(s) to the eye or less, e.g., a volume of about0.08 mL or less, such as ˜0.07 mL, ˜0.06 mL, ˜0.05 mL, ˜0.04 mL, ˜0.03mL, ˜0.02 mL, or ˜0.01 mL or less. As used herein, a description of a“strip of ointment” (or similar application of an ointment) is an amountof ointment typically used for such applications in the art or less,such as a strip of ¾″ or less, such as an ˜half-inch strip, ˜onethird-inch strip, ˜one quarter inch strip, or less (e.g., ˜3 cm, ˜2 cm,˜1 cm, or -one-half cm or less).

According to certain aspects, the formulations described herein maintainthe compounds of the invention in contact with the ocular surface(mucous membrane) of the eye for at least about 2 hours afterapplication, such as for at least ˜4 hours, at least ˜8 hours, at least˜16 hours, at least ˜20 hours, or for example at least about 24 hoursafter application. According to some facets, the formulationsdemonstrate at least about 5% higher, such as at least ˜1% higher, atleast ˜2% higher, at least ˜3% higher, at least ˜4% higher, at least ˜5%higher, at least ˜6% higher, at least ˜7% higher, at least ˜8% higher,at least ˜9% higher, or at least ˜10% higher patient compliance ascompared to TOBREX® as assessed by conducting two or more adequatelypowered and controlled as would be acceptable by a major regulatoryauthority, e.g., the United States FDA. In certain aspects, formulationsdescribed herein demonstrate at least 5% better, such as at least ˜1%better, at least ˜2% better, at least ˜3% better, at least ˜4% better,at least ˜5% better, at least ˜6% better, at least ˜7% better, at least˜8% better, at least ˜9% better, or at least ˜10% better efficacy ascompared to TOBREX® as assessed by conducting two or more adequatelypowered and controlled as would be acceptable by a major regulatoryauthority, e.g., the United States FDA. In certain other aspects, theformulations demonstrate at least 5% less, such as at least ˜1% less, atleast ˜2% less, at least ˜3% less, at least ˜4% less, at least ˜5% less,at least ˜6% less, at least ˜7% less, at least ˜8% less, at least ˜9%less, or at least ˜10% less toxicity, e.g., surface toxicity, ascompared to TOBREX® as assessed by conducting two or more adequatelypowered and controlled as would be acceptable by a major regulatoryauthority, e.g., the United States FDA. In aspects, the formulationsdemonstrate that on average fewer than 2 people in 100 treated with theformulation experience a hypersensitivity or localized ocular toxicityreaction such as lid itching and swelling, and conjunctival erythema asassessed by one or more physicians in an appropriately poweredpopulation of patients or by an appropriately powered clinical study.

Methods of Use

In aspects, the invention provides methods of treating conditions ordisorders of a mammalian eye, e.g., an eye infected with an infectiveagent, comprising administering to the eye an ophthalmologicallysuitable pharmaceutical formulation, comprising an ophthalmologicallysuitable pharmaceutical composition which comprises an effective amountof an antimicrobial active pharmaceutical ingredient (API) whichcomprises an effective amount of a compound having a structure accordingto Formula I, Formula II, or Formula III described herein, wherein thecompound is complexed with a lipophilic and amphoteric complexing agent,and further wherein the complexing agent detectably promotes the uptakeof the composition by corneal cells, the retention of the complex bycorneal cells, or both, as compared to the free compound. In aspectssuch formulations comprise one or more additional ophthalmologicallysuitable pharmaceutical ingredients. In aspects, the one or moreadditional active pharmaceutical ingredients is/are directed to furthersupporting the treatment of the primary indication for which thecomplexed compounds of the composition are directed (e.g., an infectionof the eye or its adnexa), directed to addressing one or more conditionsrelated to the primary indication (e.g., inflammation associated with aninfection of the eye or its adnexa), or both. In aspects such anadditional active can be an antimicrobial (e.g., antibacterial) agent.In aspects, such an additional active can be an anti-inflammatory agent.

According to certain aspects, the invention comprises a method ofreducing the level of bacterial infection present in an eye comprisingapplication of a formulation described herein. In aspects, describedherein is a method of using a disclosed formulation to treat a patientsuffering from an ocular disease or condition which may be sensitive to,e.g., susceptible to, or treated by, such a formulation. In some suchapplications, the disease or condition is an external infection of theeye, where in some aspects the external infection is caused by pathogenselected from a group comprising a gram positive or a gram-negativeophthalmic pathogen, e.g., Staphylococci, such as S. Aureus and S.epidermis. In aspects, infective agents treatable by formulationsdescribed herein can further include Haemophilus influenza,Streptococcus pneumoniae, Pseudomonas aeruginosa. In aspects, aninfective agent treatable by the formulations described herein can bedescribed as a coagulase-negative staphylococcus, a streptococci, or agram-negative bacilli. In certain aspects, the pathogen is a penicillinresistant strain. In aspects, the formulations herein are capable oftreating ocular infective agents which may not have responded tocurrent-on market drugs, or which have not effectively responded to aprevious treatment. Examples of organisms which may be treatable byformulations described herein and, in further aspects, which may betreatable by formulations herein after having previously beenunresponsively treated with a prior treatment include but may not belimited to Staphylococcus aureus, Streptococcus (including Streptococcuspneumoniae), Escherichia coli, Haemophilus influenzae,Klebsiella/Enterobacter species, Moraxella lacunata, and, e.g.,Neisseria species.

In certain aspects, formulations successful in such methods comprise oneor more compounds of the invention in a concentration of between about0.1-about 10% w/v, such as for example between ˜0.1-˜5% w/v, 0.1-˜4%w/v, 0.1-˜3% w/v, ˜0.1-˜2% w/v, ˜0.1-˜1% w/v, or for example between˜0.3-˜5% w/v, as in for example between ˜0.6-5% w/v, between ˜1-3% w/v,or for example approximately 2.5% w/v. In certain aspects, wherein theformulation comprises a complexing agent, formulations successful insuch methods comprise one or more complexing agents described herein ina concentration of between ˜0.1-˜10% w/v, such as for example between˜0.1-˜5% w/v, 0.1-˜4% w/v, 0.1-˜3% w/v, ˜0.1-˜2% w/v, ˜0.1-˜1% w/v, orfor example between ˜0.3-˜5% w/v, as in for example between ˜0.6-5% w/v,between ˜1-3% w/v, or for example approximately 2.5% w/v.

According to aspects, the formulations described herein can beadministered four times per day or less and achieve efficacious results.In aspects, the formulations can be administered less frequently, suchas, e.g., three times per day or less, twice per day or less, or in someinstances the formulations can be administered once per day (e.g., oncedaily), such as, e.g., effective treatment can be attained by applyingformulation(s) described herein to an infected eye no more than fourtimes per 24-hour period (e.g., per day), 3 times per day, 2 times perday, or for example no more than once per day. In aspects, a singletreatment is a single drop of formulation. In other aspects, a singletreatment is two drops of formulation. Therefore, in facets, effectivetreatment of an ocular infection can be attained by applying a singledrop of a formulation described herein to the infected eye 4×/24-hourperiod, 3×/24-hour period, 2×/24-hour period, or once/24-hour period. Inaspects, two drops of a formulation described herein applied to theinfected eye 2×-4×/24-hour period or once/24-hour period can effectivelytreat an ocular infection.

In embodiments, a formulation comprises a complexed compound in solutionfor administration via drops to the eye approximately twice daily forthe treatment of an external infection of the eye.

In aspects wherein corneal permeation is statistically increased, theonset of symptom improvement following a standard administrationprotocol is detectably or significantly faster, such as for example atleast ˜2 hours faster, at least ˜4 hours faster, at least ˜6 hoursfaster, at least ˜8 hours faster, at least ˜12 hours faster, at least˜16 hours faster, at least ˜20 hours faster, or, for example at least˜24 hours faster, than that of the non-complexed compound, as assessedby a qualified professional or as self-reported in an appropriatelycontrolled study of a patient population. In certain facets, a singlecourse of administration of a treatment comprising the compositionresolves the condition for which the course of administration isprescribed at least about 1% more frequently, such as about 2%, ˜3%,˜4%, ˜5%, ˜6%, ˜7%, ˜8%, ˜9%, or ˜10% more frequently or even highersuccess rates after a single course of administration comprising acomplexed compound than a single course of administration of treatmentcomprising a similar composition comprising a non-complexed compound asassessed by conducting two or more adequately powered and controlledstudies, as would be acceptable by a major regulatory authority, e.g.,the United States FDA.

According to some aspects wherein corneal permeation is detectably orsignificantly, e.g., statistically increased, and administration of acomposition comprising a complexed compound within a formulationrequires an administration rate of no more than two thirds, such as nomore than one halve and, in some cases no more than one third of thetotal number of doses required for a similar composition comprising anon-complexed compound over the same course of treatment.

According to certain facets wherein corneal cell retention/uptake isdetectably or significantly increased, the onset of symptom improvementis at least detectably faster, such as for example at least ˜2 hoursfaster, at least ˜4 hours faster, at least ˜6 hours faster, at least ˜8hours faster, at least ˜12 hours faster, at least ˜16 hours faster, atleast ˜20 hours faster, or, for example at least ˜24 hours faster, incompositions and formulations comprising a complexed compound than thatof a similar composition comprising a non-complexed compound, asassessed by a qualified professional or as self-reported in anappropriately controlled assessment of a patient population, or, forexample, as assessed by conducting two or more adequately powered andcontrolled studies as would be acceptable by a major regulatoryauthority, e.g., the United States FDA. The terms “retention” and“uptake” in this and in any other aspect of this disclosure can be usedinterchangeably herein to describe the type of effect exemplified in theExamples below, in which a greater amount of API is in corneal cellsafter a period of administration.

In certain aspects wherein retention is increased, a single course ofadministration of a treatment comprising a composition and/orformulation comprising a complexed compound resolves the condition forwhich the course of administration is prescribed at least about 1% morefrequently, such as at least ˜1%, ˜2%, ˜3%, ˜4%, ˜5%, ˜6%, ˜7%, ˜8%,˜9%, or at least ˜10% more frequently than a single course ofadministration of a treatment comprising a similar composition with anon-complexed compound as assessed by conducting two or more adequatelypowered and controlled clinical studies (“studies”) as would beacceptable by a major regulatory authority, e.g., the United States FDA.

In facets wherein retention is increased, a composition or formulationcomprising a complexed compound requires an administration rate of nomore than two thirds, e.g., no more than one half, and in facets no morethan one third of the total number of doses required for a similarcomposition comprising a non-complexed compound over the same course oftreatment.

According to some aspects wherein retention is increased, the rate ofantibiotic resistance in a population receiving the compositioncomprising a complexed compound is significantly less than the rate ofantibiotic resistance in a population having received a similarcomposition comprising a non-complexed compound.

According to certain facets wherein both corneal permeation and cornealretention is increased, the onset of symptom improvement is at leastdetectably faster, such as for example at least ˜2 hours faster, atleast ˜4 hours faster, at least ˜6 hours faster, at least ˜8 hoursfaster, at least ˜12 hours faster, at least ˜16 hours faster, at least˜20 hours faster, or, for example at least ˜24 hours faster, for aformulation comprising a complexed compound than that of a similarcomposition comprising a non-complexed compound, as assessed by aqualified professional or as self-reported in an appropriatelycontrolled assessment of a patient population or as assessed byconducting two or more adequately powered and controlled studies aswould be acceptable by a regulatory authority, e.g., the United StatesFDA.

In aspects wherein both corneal permeation and corneal retention isincreased, a single course of administration of a treatment comprising acomplexed compound resolves the condition for which the course ofadministration is prescribed at least about 1% more frequently, such asat least ˜1%, at least ˜2%, at least ˜3%, at least ˜4%, at least ˜5%, atleast ˜6%, at least ˜7%, at least ˜8%, at least ˜9%, or for example atleast ˜10% or even higher than a single course of administration of atreatment comprising a similar composition with a non-complexed compoundas assessed by conducting two or more adequately powered and controlledstudies as would be acceptable for demonstrating pharmaceutical efficacyby a major regulatory authority, e.g., the United States FDA.

In aspects wherein both corneal permeation and corneal retention areincreased, the administration rate is no more than two thirds, such asno more than one half, and in certain facets no more than one third ofthe total number of doses required for a similar composition comprisinga non-complexed compound over the same course of treatment.

In aspects, the rate of antibiotic resistance in a population receivinga composition or formula comprising a non-complexed compound issignificantly less than in a population having received a similarcomposition comprising a non-complexed compound.

According to certain aspects, a formulation or composition comprising aderivatized compound which detectably increases the corneal permeation,corneal retention, or both the corneal permeation and corneal retentionof a derivatized compound results in the onset of symptom improvementwhich is significantly faster, such as for example at least ˜2 hoursfaster, at least ˜4 hours faster, at least ˜6 hours faster, at least ˜8hours faster, at least ˜12 hours faster, at least ˜16 hours faster, atleast ˜20 hours faster, or, for example at least ˜24 hours faster, thanthat of a similar composition comprising tobramycin, as assessed by aqualified professional, as self-reported in an appropriately controlledassessment of a patient population, or as assessed by conducting two ormore adequately powered and controlled clinical studies, as would bedeemed acceptable to prove efficacy by a major regulatory authority,e.g., the United States FDA.

In certain aspects wherein a formulation or composition comprising aderivatized compound detectably increases the corneal permeation,corneal retention, or both the corneal permeation and corneal retentionof a derivatized compound, a single course of administration of atreatment comprising the composition resolves the condition for whichthe course of administration is prescribed at least about 5% morefrequently, such as at least ˜6% more frequently, at least ˜7% morefrequently, at least ˜8% more frequently, at least ˜9% more frequently,or at least ˜10% more frequently or more, than a single course ofadministration of a treatment comprising a similar composition withtobramycin as measured by an appropriately controlled clinical trial.

In some facets, the administration protocol of a formulation comprisinga derivatized compound or composition comprising a derivatized compoundrequires an administration rate of no more than two thirds, such as nomore than one half, such as no more than one third of the total numberof doses required for a similar composition comprising tobramycin overthe same course of treatment.

According to some aspects, the rate of antibiotic resistance in apopulation receiving a composition or formulation comprising aderivatized compound is significantly less than the rate of antibioticresistance in a population having received a similar compositioncomprising tobramycin.

EXEMPLARY COMPLEXED COMPOUND PRODUCTION & FUNCTIONAL ASSESSMENT

To even further exemplify and illuminate aspects of the invention, thefollowing description of illustrative applications of particular aspectsof the invention is provided. These “Examples” are meant to exemplifyparticular facets of the invention but should not be used to limit thescope of the invention in any manner.

Example 1

A study was performed to examine the ability of tobramycin to form acomplex with amphoteric, lipophilic materials suitable for ophthalmicuse.

The following procedure was followed to form a tobramycin complex withhistidine material to be used for evaluation. 5 g of tobramycin and 5 gof histidine were weighed and each dissolved in 50 mL of water,tobramycin being added first and completely dissolved prior to theaddition and dissolution of histidine. The solution was then brought upto a final volume of 100 mL with water. The solution was then pouredinto open petri dishes and placed in an oven set at 40° C. and checkedfor complete drying. If plates were not completely dry after an initialcheck, they were allowed to dry for an additional 8 hours.

The following procedure was followed to form a tobramycin complex withthe amphoteric polymer Soluplus® (polyvinyl caprolactam-polyvinylacetate-polyethylene glycol graft copolymer (PCL-PVAc-PEG)) material tobe used for evaluation. 5 g of tobramycin and 5 g of Soluplus® wereweighed and dissolved in 50 mL of water, tobramycin being added firstand allowed to completely dissolve prior to the addition and completedissolution of Soluplus®. The solution was brought up to a final volumeof 100 mL with water. The solution was then poured into open petridishes and placed in an oven set at 40° C. and checked for completedrying. If plates were not completely dry, they were allowed to dry foran additional 8 hours.

After preparing the above dried compositions, the two products wereanalyzed in Differential Scanning Colorimeter (DSC) studies wherein theformation of a) a tobramycin complex with histidine and b) a tobramycincomplex with the Soluplus® polymer were evaluated. The resulting DSCdata is presented in FIGS. 1A-1D (tobramycin+histidine) and FIGS. 3A-3D(tobramycin+Soluplus®, and is summarized in Table 3, below.

TABLE 3 Summary of Differential Scanning Colorimeter (DSC) results oftobramycin complex with histidine and tobramycin complex withSoluplus ®. Sample Onset Peak Sr. Sample Weight Temperature TemperatureEnthalpy No Description (mg) (° C.) (° C.) (J/g) 1 Tobramycin, 4.546First: 144.68 First: 153.07 First: 39.494 USP Second: 221.23 Second:223.25 Second: 17.719 2 Histidine USP 4.864 284.75 287.56 NA 3Tobramycin + 6.309 First: 142.57 First: 149.70 First: 44.146 HistidineSecond: 219.29 Second: 220.43 Second: 29.296 physical mixture Third:255.07 Third: 260.86 Third: 118.01 4 Tobramycin + 7.225 260.04 276.32314.96 Histidine complex ppt from solution 5 Tobramycin, 4.546 First:144.68 First: 153.07 First: 39.494 USP Second: 221.23 Second: 223.25Second: 17.719 6 Soluplus in 6.46 247.03 250.68 10.3 water 7Tobramycin + 6.16 First: 145.35 First: 151.65 First: 38.733 SoluplusSecond: 231.64 Second: 223.33 Second: 30.463 physical mixture 8Tobramycin + 6.96 First: 135.08 First: 147.48 First: 41.778 SoluplusSecond: 192.54 Second: 194.88 Second: 57.765 complex ppt from solution

The results show that tobramycin forms a complex with both histidine andSoluplus® (again, chemically the amphoteric polymer polyvinylcaprolactam-polyvinyl acetate-polyethylene glycol graft copolymer). FIG.1A shows the resulting DSC curve for tobramycin alone. FIG. 11B showsthe resulting curve for histidine alone. As shown above, the tobramycinhistidine complex precipitated from solution, forming a new peak at theonset temperature of 260.04° C. and having the peak at 276.32° C. FIG.1C illustrates that while in the physical mixture of histidine andtobramycin, both peaks of tobramycin, one peak of histidine and one peakof complex are visible. FIG. 1D shows the resulting curve for thetobramycin+histidine complex.

In case of Soluplus®, the DSC tobramycin peaks are shifted to lowertemperatures (see FIGS. 3C and 3D). FIG. 3A shows the resulting peak oftobramycin alone. FIG. 3B shows the resulting peak of Soluplus® alone.The onset temperature of the first peak of tobramycin that starts at144.68° C. is shifted to 135.08° C. and onset temperature of the secondpeak that starts at 221.23° C. is shifted to 192.54° C. in the mixture(see FIGS. 3C and 3D). Similarly, the peak temperatures also shifted tolower temperatures, from 153.07° C. to 147.48° C. and from 223.25° C. to194.88° C. The change in the peak temperature of the second peak fortobramycin shows the formation of the complex.

Tobramycin+histidine complexes and tobramycin+Soluplus® complexes werethen analyzed by Fournier transform infrared (FTIR) to better understandthe structure of the two complexes. This data is presented in FIGS. 2Aand 2B (tobramycin alone and histidine alone, respectively) and 2C(tobramycin+histidine precipitated from solution), as well as FIGS. 4Aand 4B (tobramycin alone and Soluplus® alone) and 4C(tobramycin+Soluplus® precipitated from solution).

The FTIR tobramycin and histidine complex analysis reveals that a newpeak appears at 3016 cm-1. Further, N—H stretching in tobramycin ischanged to 1567 cm-1. The peak for N—H and O—H bending is absent, whilethe C═O stretching for histidine is changed to 1632 cm-1, and the C═Sstretching for histidine is changed to 1413 cm-1.

The FTIR tobramycin Soluplus® complex analysis results specificallyreveal that a N—H stretching peak for tobramycin (1579 cm-1) is absent.The peak at 1633 cm-1 of Soluplus® changed to 1600 cm-1.

The FTIR and DSC data of this experiment combine to demonstrate thesuccessful formation of both tobramycin+histidine andtobramycin+Soluplus® complexes. Generation of such complexes led to theplanning of further experimentation to evaluate the ability of suchcomplexes to increase the corneal permeability and retention oftobramycin, such an aim being indicative of the potential for successfuldevelopment of a novel treatment for certain ophthalmic disorders suchas infection having a reduced dosing frequency.

Example 2

A study was conducted to evaluate tobramycin+histidine andtobramycin+Soluplus® complexes for trans-corneal transport capability.The aim of this study was to determine whether the tobramycin in complexform was capable of increased corneal permeation and/or cornealretention over tobramycin alone.

The formulations as shown in table 4 were prepared for use in thetrans-corneal transport evaluation experiment.

TABLE 4 Formulations of tobramycin and Soluplus ® for use intrans-corneal transport evaluation. NaCl conc. Sr. Complexing forosmolality Osmolality No. Tobramycin Agent adjustment (mOsm/Kg) pH 12.5% w/v None 0.47% w/v 313 7.39 2 2.5% w/v Histidine: None 325 7.4 2.5%w/v 3 2.5% w/v Soluplus: 0.40% w/v 312 7.37 2.5% w/v

Steps for preparing the solutions described in Table 2 were as follows.To prepare the tobramycin 2.5% solution (used as a control), 2.5 g oftobramycin and 0.45 g of sodium chloride were weighed and dissolved in50 mL of water, tobramycin being added and completely dissolved prior tothe addition and complete dissolution of sodium chloride. The volume ofthe solution was then brought up to about 90 mL at which point the pHwas adjusted to as close to 7.4 as possible using 0.1 N HCl or 0.1 NNaOH. The final solution volume was then brought up to 100 mL withwater. To prepare the preparations of 2.5% tobramycin and 2.5% histidineor 2.5% Soluplus®, the same procedure was followed except 2.5 g ofhistidine or 2.5 g of Soluplus® was weighed in place of 0.45 g of sodiumchloride. All other procedural steps remained the same.

The trans-corneal transport study of the tobramycin+histidine andtobramycin+Soluplus® complexes, with tobramycin alone as the control,was conducted across human corneal cells. The study was conducted in 24well plates with N=6. The study comprised two parts: a firstpermeability assessment and a second retention assessment.

Results from the permeability assessment are shown in Table 5 below,with the permeability graphs of the three samples plotted and depictedin FIG. 5. In FIG. 5, tobramycin alone is shown in the graph with asquare indicator; tobramycin+Histidine is shown with a circle-shapedindicator; and tobramycin+Soluplus® is shown with a triangularindicator.

TABLE 5 Transport of tobramycin across cultured human cornea from threedifferent formulations including tobramycin + histidine and tobramycin +Soluplus ® complexes compared to non-complexed tobramycin. TobramycinTobramycin Tobramycin Time (2.5%) + sodium (2.5%) + (2.5%) + pointchloride (0.47%) Histidine (2.5%) Soluplus (2.5%) (min) (ppm) (ppm)(ppm) 15 2.9 2.8 2.7 30 6.0 6.6 8.0 60 11.0 14.1 15.4 120 34.1 32.2 43.3180 39.2 46.9 52.2 360 172.0 211.8 252.0

The above data demonstrate that the permeation across human cornealcells of tobramycin complex solutions with either histidine or Soluplus®are each faster than a non-complexed tobramycin product, such as acurrently marketed tobramycin product, comparable formulation comprisingnon-complexed tobramycin, or both.

For the retention assessment, the concentration of tobramycin in donorchambers of the three solutions was measured, at the end of theexperiment at time point 6 hours (360 minutes). The data collected isshown in graphical form as FIG. 6, with the raw data shown below inTable 6.

TABLE 6 Human corneal cell permeability of tobramycin + histidine andtobramycin + Soluplus ® complexes compared to non-complexed tobramycin.Conc at 360 mins Conc diff from Formulation in donor (mg/mL) initial(mg/mL) Tobramycin (2.5%) + 19.4 5.7 sodium chloride (0.47%) Tobramycin(2.5%) + 17.5 7.5 Histidine (2.5%) Tobramycin (2.5%) + 19.4 5.6 Soluplus(2.5%) + Sodium chloride (0.40%)Based on the data depicted in FIG. 6, it is clear that the donor chamberconcentration of the tobramycin+histidine complex is depleting rapidlyand only a small amount appears in the receiving chamber. Most of thetobramycin taken up from the donor solution is being retained by cornea.This retention forms a depot of tobramycin in the cornea and is likelyto get released in front of the eye over a period. This result isindicative of the ability to reduce the dosing frequency when utilizinga formulation comprising such a composition.

It should be understood that the above description and incorporatedexamples are intended to be illustrative and not restrictive. Manyembodiments will be apparent to those of skill in the art upon readingthe above description. The scope of the invention should, therefore, bedetermined with reference to the appended aspects and/or claims, alongwith the full scope of equivalents to which such claims are entitled.The disclosures of all articles and references, including patents,patent applications and publications, are incorporated herein byreference in their entirety and for all purposes.

Example 3

A study was conducted to evaluate tobramycin+histidine complexes incontrolling infection of a mammalian eye, specifically a mammalian eyeinfected with Staphylococcus Aureus (S. Aureus).

Twelve healthy rabbits were selected using proper husbandry procedures.All rabbits were anesthetized by instilling proparacaine eye drops inboth eyes. Rabbits were then injected with 50 μL suspension ofStaphylococcus Aureus in trypticase soy broth (TSB) at a concentrationof 10,000 CFU/mL, the injections being applied to each rabbit eyeintra-stromally. The S. Aureus infection was allowed to grow in rabbiteyes for 12 hours.

After 12 hours, the rabbits were divided into two groups of six (6)rabbits. At 12 hours post administration of the infective agent, thefirst group of rabbits was dosed with a formulation (“reference”) oftobramycin (similar to or the same as the marketed formulation TOBREX®)in their right eye. The second group of rabbits was dosed with the testformulation (“test”) of Tobramycin 0.3% in their right eye. The left eyeof each rabbit received a drop of saline. At 24 hours post firstadministration of the infective agent, a second dose of “reference”formulation, and a second dose of “test” formulation (tobramycin (0.3%))were again administered to the right eye of each respective test group.The formulations of reference and test solutions are shown below inTable 7 and Table 8.

TABLE 7 Reference Formulation Sr. No. Ingredients Qty/mL 1 Tobramycin3.0 mg 2 BKC as 10% Soln. 0.1 mg 3 Boric Acid 12.4 mg  4 Sodium Sulfate1.52 mg  5 Tyloxapol 1.0 mg 6 Sodium Chloride 2.78 7 Sodium HydroxideQS, pH adjust 8 Sulfuric acid QS, pH adjust 9 Water of Injection QS, 1mL

TABLE 8 Test Formulation Comprising 0.3% Tobramycin/0.3% Histidine Sr.No. Ingredients Qty/mL 1 Tobramycin 3 mg 2 Histidine 3 mg 3 SodiumChloride 7.48 mg   4 Sodium Hydroxide QS, pH adjust 5 Sulfuric acid QS,pH adjust 6 Water for Injection QS, 1 mL

At 25 hours post administration of the first dose of infective agent (1hour post administration of the second dose of infective agent), tearsamples were collected using sterile tear strips. Tear strips were thenplaced in 1.0 mL of TSB solution. 0.25 mL of the resulting solution wasplated onto TS agar plates. Bacterial colonies were enumerated followingovernight incubation at 37° C. Bacterial densities were estimated atLog₁₀ CFU/mL of tear.

Colony forming unit (CFU) data is provided in FIG. 7. FIG. 7 showscolony forming units (CFU)s present in the tear sample(s) after 2 dosesof reference formulation (again, similar TOBREX® (0.3%), marketedformulation) in the right eye compared to the vehicle (absent the API)in the left eye. Again, the first dose was given after 12 hours ofinitial infection of Staphylococcus Aureus and the second dose was givenafter 24 hours of the infection. The first tear sample was collected at25 hours after the first dose (1 hour after the second dose). As shown,CFUs counts drop when reference formulation is instilled in the eye.However, notably, the bacterial count grows back (increases); see theupward trend line starting at between 28- and 30-hourspost-administration in FIG. 7. In comparison, see FIG. 8. FIG. 8illustrates CFUs present in tear sample after 2 doses of tobramycin(0.3%)+histidine (0.3%) formulation in the right eye compared to thevehicle (absent API) in the left eye. Again, the first dose wasadministered after 12 hours of initial infection of StaphylococcusAureus and the second dose was administered at 24 hours post-infection.The first tear sample was collected at 25 hours post-initial infection,or 1 hour after the second dose. As shown in FIG. 8, when tobramycin(0.3%) formulation with histidine (test formulation) is instilled, theCFU count drops a bit more quickly. See the steeper trend from timepoint 24 hours to time point about 17 hours in FIG. 8 versus FIG. 7).Further, the CFU count does not then grow back (increase). Thisindicates that the histidine-containing formulation creates a smalldepot in the cornea, from which that active gets released, or is beingreleased into the eye at a later time, in any case preventing furthergrowth.

Of particular note is that the reference product contains benzalkoniumchloride (BKC). Benzalkonium chloride is absent in the test formulationcomprising histidine. It is well known in the art that BKC can aid inreducing bacterial load. In this study, the histidine containingformulation outperformed the formulation containing BKC.

Example 4

Similar studies to those exemplified in Example 3 were performed usingdifferent bacteria, Pseudomonas Aeruginosa. In this Example, theinfection was allowed to grow for 24 hours prior to the firstadministration of reference product or test formulation. A firsttreatment was instilled at 24 hours post-infection and a second dose wasadministered at 36 hours post-infection. The reference formulation andfirst test formulation tested in this study were the same as thosepresented in Example 3. This study further included the testing of asecond test formulation, this formulation comprisingtobramycin+histidine in higher concentrations. This second testformulation is shown in Table 11 below. Other than requiring additionalanimals, the test protocol was otherwise similar to Example 3. The firsttear samples were collected at 37 house post-infection, or 1 hour afteradministration of the second dose of treatment.

TABLE 11 Test Formulation Comprising 0.6% Tobramycin/0.6% Histidine Sr.No. Ingredients Qty/mL 1 Tobramycin 6.0 mg 2 Histidine 6.0 mg 3 SodiumChloride 6.24 mg  4 Sodium Hydroxide QS, pH adjust 5 Sulfuric acid QS,pH adjust 6 Water for Injection QS, 1 mL

FIG. 9 presents the CFUs present in the tear sample(s) after the 2 dosesof reference formulation (once again, similar to the marketedformulation of TOBREX® (0.3%)) in the right eye compared to vehicle(formulation absent API) in the left eye. FIG. 10 presents the CFUspresent in tear sample after 2 doses of tobramycin (0.3%)+histidine(0.3%) formulation in the right eye compared to the vehicle (formulationabsent API) in the left eye. FIG. 11 presents the CFUs present in tearsample after 2 doses of tobramycin (0.6%)+histidine (0.6%) formulationin the right eye compared to the vehicle in the left eye.

As demonstrated by comparing FIGS. 9 and 10, the first test formulation(Tobramycin (0.3%)+Histidine (0.3%)) reduced the number of CFUs about 5hours faster than that of the reference formulation. As demonstrated bycomparing FIGS. 9 and 11, the second test formulation (Tobramycin(0.6%)+Histidine (0.6%)) reduced the number of CFUs about 6 hours fasterthan that of the reference formulation.

The results of this study demonstrate that both test formulationsoutperformed the reference formulation in the amount of time required todemonstrate a significant reduction (e.g., a reduction to 0 ornon-detectable CFU/mL tears) in levels of infective agent present incollected tear solutions. Further, both test formulations were capableof maintaining the reduced level of infective agents through the timeperiod studied.

Exemplary Aspects of the Invention

The following is a first set of non-limiting, exemplary aspects of theinvention, which is intended to highlight some of the variousembodiments of the invention.

In aspects, the invention comprises an ophthalmic tobramycin complex forinstillation in the eye comprising tobramycin complexed with materialthat is suitable for ophthalmic use (aspect 1).

In aspects, the invention comprises the ophthalmic tobramycin complex ofaspect 1, wherein the material suitable for ophthalmic use compriseshistidine or polyvinyl caprolactam-polyvinyl acetate-polyethylene glycolgraft co-polymer (PCL-PVAc-PEG) or its derivatives (aspect 2).

In aspects, the invention comprises the ophthalmic tobramycin complex ofaspect 1 or aspect 2, wherein the amount of tobramycin and material thatis suitable for ophthalmic use in the complex is about 1.0% to about 10%by weight (aspect 3).

In aspects, the invention comprises the ophthalmic tobramycin complex ofany one or more of aspects 1-3, wherein the tobramycin complex isformulated as solution, suspension, emulsion, or a dispersion (aspect4).

In aspects, the invention comprises the ophthalmic tobramycin complex ofaspect 4, wherein the tobramycin complex is formulated as an ophthalmicsolution (aspect 5).

In aspects, the invention comprises the ophthalmic solution of aspect 5,wherein the solution is applied once, twice, or three times daily(aspect 6).

In aspects, the invention comprises the ophthalmic solution of aspect 5or aspect 6, wherein the instillation of solution in the eye allows toreduce the daily dosage frequency, improves compliance, duration andeffect of tobramycin for the treatment of external infections of the eyeand its adnexa caused by susceptible bacteria (aspect 7).

In aspects, the invention is a method of treating an infection of theeye or its adnexa comprising topically administering to the eye asolution composition comprising tobramycin complexed with histidine orPCL-PVAc-PEG or its derivatives, wherein the solution composition allowsfor efficacy in treating the infection with a once, twice or three timesper day dosing schedule (aspect 8).

In aspects, the invention comprises the method of treating infections ofthe eye or its adnexa of aspect 8, wherein the tobramycin is complexedwith histidine (aspect 9).

In aspects, the invention comprises the method of treating infections ofthe eye or its adnexa of aspect 8, wherein the tobramycin is complexedwith PCL-PVAc-PEG or its derivatives (aspect 10).

In aspects, the invention comprises the method of treating infections ofthe eye or its adnexa of any one or more of aspects 8-10, wherein theamount of tobramycin is about 0.3% to about 5.0% by weight (aspect 11).

In aspects, the invention comprises the method of treating infections ofthe eye or its adnexa of aspect 11, wherein the amount of tobramycin isabout 2.5% to about 5.0% by weight (aspect 12).

In aspects, the invention comprises the method of treating infections ofthe eye or its adnexa of any one or more of aspects 8-12, wherein theamount of histidine or PCL-PVAc-PEG or its derivatives is about 1.0% toabout 10% by weight (aspect 13).

In aspects, the invention comprises the method for treating infectionsof the eye or its adnexa of aspect 13, wherein the amount of histidineor PCL-PVAc-PEG or its derivatives is about 2.5% to about 5.0% by weight(aspect 14).

In aspects, the invention is an ophthalmic tobramycin formulationcomprising tobramycin complexed with histidine or PCL-PVAc-PEG or itsderivatives, wherein the dosage form of the ophthalmic tobramycinformulation retains at least 90% w/w of the potency of tobramycin whenstored at 25° C. and 60% relative humidity or at 40° C. and 75% relativehumidity for 3 months (aspect 15).

In aspects, the invention is a pharmaceutical composition comprising anantimicrobial active pharmaceutical ingredient (API) comprising aneffective amount of a compound having a structure according to theformula

wherein (1) R¹ is —CH—NH₂ (i.e., Me—NH₂) or an optionally substitutedalkyl, an optionally substituted aryl, an optionally substitutedaralkyl, an optionally substituted cycloalkyl, an optionally substitutedcycloalkylalkyl, an optionally substituted heterocyclyl, an optionallysubstituted heterocyclylalkyl, an optionally substituted heteroaryl, oran optionally substituted heteroarylalkyl; (2) R⁴, R⁶, R⁸, and R⁹ are—NH₂ or an optionally substituted alkyl, an optionally substituted aryl,an optionally substituted aralkyl, an optionally substituted cycloalkyl,an optionally substituted cycloalkylalkyl, an optionally substitutedheterocyclyl, an optionally substituted heterocyclylalkyl, an optionallysubstituted heteroaryl, or an optionally substituted heteroarylalkyl;(3) R² is —Me—OH or an optionally substituted alkyl, an optionallysubstituted aryl, an optionally substituted aralkyl, an optionallysubstituted cycloalkyl, an optionally substituted cycloalkylalkyl, anoptionally substituted heterocyclyl, an optionally substitutedheterocyclylalkyl, an optionally substituted heteroaryl, or anoptionally substituted heteroarylalkyl; and (4) R³, R⁵, R⁷ and R¹⁰ are—OH or an optionally substituted aryl, an optionally substitutedaralkyl, an optionally substituted cycloalkyl, an optionally substitutedcycloalkylalkyl, an optionally substituted heterocyclyl, an optionallysubstituted heterocyclylalkyl, an optionally substituted heteroaryl, oran optionally substituted heteroarylalkyl (Formula I); complexed with alipophilic and amphoteric complexing agent, wherein the composition isophthalmologically safe and the complexing agent detectably promotes theuptake of the composition by corneal cells, the retention of the complexby corneal cells, or both, as compared to the free compound (aspect 16).

In aspects, the invention is the pharmaceutical composition of aspect16, wherein no more than three of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹,and R¹⁰ differ in composition from the corresponding position intobramycin (aspect 17).

In aspects, the invention is the pharmaceutical composition of aspect17, wherein no more than two of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, andR¹⁰ differ from the corresponding position in tobramycin (aspect 18).

In aspects, the invention is the pharmaceutical composition of aspect18, wherein no more than one of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, andR¹⁰ differs from the corresponding position in tobramycin (aspect 19).

In aspects, the invention is the pharmaceutical composition of aspect16, wherein the compound has a structure according to Formula II (aspect20).

In aspects, the invention is the pharmaceutical composition of aspect20, wherein no more than three of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, and R⁸differ from the corresponding position in tobramycin (aspect 21).

In aspects, the invention is the pharmaceutical composition of aspect20, wherein no more than two of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, and R⁸differ from the corresponding position in tobramycin (aspect 22).

In aspects, the invention is the pharmaceutical composition of aspect22, wherein no more than one of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, and R⁸differ from the corresponding position in tobramycin (aspect 23).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 20-22, wherein R², R⁷, or both are the same as thecorresponding positions in tobramycin (aspect 24).

In aspects, the invention is the pharmaceutical composition of aspect24, wherein R² is a —Me—Oh and R⁷ is an —OH (i.e., these positions havethe same composition as the corresponding positions in tobramycin)(aspect 25).

In aspects, the invention is the pharmaceutical composition of aspect20, wherein the compound has a structure according to Formula III(aspect 26).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 16-26, wherein any R group that differs fromtobramycin includes an optionally derivatized 2-20 atom backbone alkylor heteroalkyl group, optionally attached through an ester or amide bondat a position corresponding to an —OH or —NH₂ group in tobramycin(aspect 27).

In aspects, the invention is the pharmaceutical composition of aspect27, wherein the alkyl or heteroalkyl group is a linear alkyl orheteroalkyl compound (aspect 28).

In aspects, the invention is the pharmaceutical composition of aspect28, wherein the group is or generally consists of a fatty acid, fattyacid derivative, short fatty acid, or short fatty acid derivative(aspect 29).

In aspects, the invention is the pharmaceutical composition of aspect29, wherein the group is or generally consists of an acetic acid, aceticacid derivative, palmitic acid, or palmitic acid derivative (aspect 30).

In aspects, the invention is the pharmaceutical composition of aspect30, wherein the alkyl or heteroalkyl group comprises one or more —C═O or—NH₂ derivative groups bound to the backbone (aspect 31).

In aspects, the invention is the pharmaceutical composition of aspect31, wherein the group comprises at least one —C═O group and at least one—NH₂ group bound to the backbone (aspect 32).

In aspects, the invention is the pharmaceutical composition of aspect28, wherein the group comprises no —C═O groups (aspect 33).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 31-33, wherein the group comprises at least two —NH₂groups bound to the backbone (aspect 34).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 27-34, wherein the backbone of the group is aheteroalkyl structure comprising at least one nitrogen, at least onethiol/sulfur, or both (aspect 35).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 27-35, wherein at least about 90% of the atoms of thebackbone are carbons (aspect 36).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 27-36, wherein the backbone comprises or is bound toan optionally derivatized 3-9-membered cycloalkyl or heterocycloalkylring (aspect 37).

In aspects, the invention is the pharmaceutical composition of aspect37, wherein the backbone comprises or is bound to a 3-6 membered ringwherein the ring comprises one or more nitro groups, is bound to one ormore nitro groups, or is bound to one or more side chains bound to oneor more nitro groups (aspect 38).

In aspects, the invention is the pharmaceutical composition of aspect 37or aspect 38, wherein the group comprises only one ring (aspect 39).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 16-39, wherein the compound is a tobramycinderivative (aspect 40).

In aspects, the invention is the pharmaceutical composition of aspect40, wherein the tobramycin derivative exhibits detectably fasterpenetration of corneal cells than tobramycin, detectably betterretention in corneal cells than tobramycin, or both (aspect 41).

In aspects, the invention is the pharmaceutical composition of aspect26, wherein the compound is tobramycin (aspect 42).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 16-42, wherein the complexing agent is a heterocycliccompound comprising at least one five to seven-member nitrogenous ringcomprising an attached chain of at least 3 carbons and at least onecarboxylic acid group (aspect 43).

In aspects, the invention is the pharmaceutical composition of aspect43, wherein the complexing agent is an amino acid (aspect 44).

In aspects, the invention is the pharmaceutical composition of aspect44, wherein the complexing agent is histidine (aspect 45).

In aspects, the invention is the pharmaceutical composition of aspect44, wherein the complexing agent is an ophthalmologically acceptablederivative of histidine (aspect 46).

In aspects, the invention is the pharmaceutical composition of aspect43, wherein the complexing agent is an ophthalmologically safe copolymer(aspect 47).

In aspects, the invention is the pharmaceutical composition of aspect47, wherein the complexing agent is polyvinyl caprolactam-polyvinylacetate-polyethylene glycol graft co-polymer (PCL-PVAc-PEG) (aspect 48).

In aspects, the invention is the pharmaceutical composition of aspect47, wherein the complexing agent is a derivative of PCL-PVAc-PEG (aspect49).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 16-49, wherein the composition is present within aformulation, and the compound is present in a concentration of betweenabout 0.1-about 10% w/v (aspect 50).

In aspects, the invention is the pharmaceutical composition of aspect50, wherein the composition is present within the formulation, and thecompound is present in a concentration of between about 0.3-about 5% w/v(aspect 51).

In aspects, the invention is the pharmaceutical composition of aspect51, wherein the composition is present within the formulation, and thecompound is present in a concentration of between about 0.6-about 5% w/v(aspect 52).

In aspects, the invention is the pharmaceutical composition of aspect52, wherein the composition is present within the formulation, and thecompound is present in a concentration of between about 1 and about 3%w/v (aspect 53).

In aspects, the invention is the pharmaceutical composition of aspect53, wherein the composition is present within the formulation, and thecompound is present in a concentration of approximately 2.5% w/v (aspect54).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 50-54, wherein the complexing agent is present withinthe formulation at a concentration of between about 0.1% and about 10%w/v (aspect 55).

In aspects, the invention is the pharmaceutical composition of aspect55, wherein the complexing agent is present within the formulation at aconcentration of between about 0.3-5% w/v (aspect 56).

In aspects, the invention is the pharmaceutical composition of aspect56, wherein the complexing agent is present within the formulation at aconcentration of between about 0.6-5% w/v (aspect 57).

In aspects, the invention is the pharmaceutical composition of aspect57, wherein the complexing agent is present within the formulation at aconcentration of between about 1-3% (aspect 58).

In aspects, the invention is the pharmaceutical composition of aspect58, wherein the complexing agent is present within the formulation at aconcentration of approximately 2.5% (aspect 59).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 16-59, wherein the rate of cornea cell permeation isfaster for the compound in complexed form than the non-complexedcompound, such that the amount of compound in the cornea increases by atleast about 15% or more after a period of 60 minutes from administration(aspect 60).

In aspects, the invention is the pharmaceutical composition of aspect60, wherein the concentration of compound permeating the surface of thecornea is at least 17% greater when in complexed form than innon-complexed form when measured at 360 minutes of an industry-standardcorneal permeability assay (aspect 61).

In aspects, the invention is the pharmaceutical composition of aspect61, wherein the concentration of compound permeating the surface of thecornea is at least 20% greater when in complexed form than innon-complexed form when measured at 360 minutes of an industry-standardcorneal permeability assay (aspect 62).

In aspects, the invention is the pharmaceutical composition of aspect62, wherein the concentration of compound permeating the surface of thecornea is at least 25% greater when in complexed form than innon-complexed form when measured at 360 minutes of an industry-standardcorneal permeability assay (aspect 63).

In aspects, the invention is the pharmaceutical composition of aspect63, wherein the concentration of compound permeating the surface of thecornea is at least 40% greater when in complexed form than innon-complexed form when measured at 360 minutes of an industry-standardcorneal permeability assay (aspect 64).

In aspects, the invention is the pharmaceutical composition of aspect64, wherein the concentration of compound permeating the surface of thecornea is at least 45% greater when in complexed form than innon-complexed form when measured at 360 minutes of an industry-standardcorneal permeability assay (aspect 65).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 60-65, wherein the concentration of compoundpermeating the surface of the cornea is at least about 15% or greaterafter 15 minutes from application than a corresponding amount of the APIin TOBREX® (aspect 66).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 60-66, wherein the complexing agent is histidine(aspect 67).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 60-66, wherein the complexing agent is PCL-PVAc-PEG(aspect 68).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 60-68, wherein the onset of symptom improvement isdetectably faster than that of the non-complexed compound, as assessedby a qualified professional or as self-reported in an appropriatelycontrolled study of a patient population (aspect 69).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 60-69, wherein a single course of administration of atreatment comprising the composition resolves the condition for whichthe course of administration is prescribed at least about 5% morefrequently than a single course of administration of a treatmentcomprising a similar composition comprising a non-complexed compound asmeasured by an appropriately controlled clinical trial or by post-marketmonitoring and reporting (aspect 70).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 60-70, wherein the composition requires anadministration rate of no more than two-thirds of the total number ofdoses required for a similar composition comprising a non-complexedcompound over the same course of treatment (aspect 71).

In aspects, the invention is the pharmaceutical composition of aspect71, wherein the composition requires an administration rate of no morethan one-half of the total number of doses required for a similarcomposition comprising a non-complexed compound over the same course oftreatment (aspect 72).

In aspects, the invention is the pharmaceutical composition of aspect72, wherein the composition requires an administration rate of no morethan one-third of the total number of doses required for a similarcomposition comprising a non-complexed compound over the same course oftreatment (aspect 73).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 16-73, wherein the level of retention of thecomplexed compound in the cornea is retained after 6 hours fromadministration when measured by an industry-standard corneal retentionassay (aspect 74).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 16-74, wherein the retention of the complexedcompound within the cornea is at least 15% higher than the retention ofthe non-complexed compound when measured at 360 minutes as measured by astandard corneal retention assay (aspect 75).

In aspects, the invention is the pharmaceutical composition of aspect75, wherein the retention of the complexed compound within the cornea isat least 20% higher than the retention of the non-complexed compoundwhen measured at 360 minutes as measured by a standard corneal retentionassay (aspect 76).

In aspects, the invention is the pharmaceutical composition of aspect76, wherein the retention of the complexed compound within the cornea isat least 25% higher than the retention of the non-complexed compoundwhen measured at 360 minutes as measured by a standard corneal retentionassay (aspect 77).

In aspects, the invention is the pharmaceutical composition of aspect77, wherein the retention of the complexed compound within the cornea isat least 30% higher than the retention of the non-complexed compoundwhen measured at 360 minutes as measured by a standard corneal retentionassay (aspect 78).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 74-78, wherein the compound is retained in at leastabout 15% or greater amount in corneal cells after 15 minutes than acorresponding amount of the API in TOBREX® (aspect 79).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 74-79, wherein the complexing agent is histidine(aspect 80).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 74-80, wherein the onset of symptom improvement is atleast detectably faster than that of a similar composition comprising anon-complexed compound, as assessed by a qualified professional or asself-reported in an appropriately controlled assessment of a patientpopulation (aspect 81).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 74-81, wherein a single course of administration of atreatment comprising the composition resolves the condition for whichthe course of administration is prescribed at least 5% more frequentlythan a single course of administration of a treatment comprising asimilar composition with a non-complexed compound as measured by anappropriately controlled clinical trial (aspect 82).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 74-82, wherein the composition requires anadministration rate of no more than two-thirds of the total number ofdoses required for a similar composition comprising a non-complexedcompound over the same course of treatment (aspect 83).

In aspects, the invention is the pharmaceutical composition of aspect83, wherein the composition requires an administration rate of no morethan one half of the total number of doses required for a similarcomposition comprising a non-complexed compound over the same course oftreatment (aspect 84).

In aspects, the invention is the pharmaceutical composition of aspect84, wherein the composition requires an administration rate of no morethan one-third of the total number of doses required for a similarcomposition comprising a non-complexed compound over the same course oftreatment (aspect 85).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 74-85, wherein the rate of antibiotic resistance in apopulation receiving the composition is significantly less than the rateof antibiotic resistance in a population having received a similarcomposition comprising a non-complexed compound (aspect 86).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 16-86, wherein both the concentration of compoundpermeating the surface of the cornea is at least 17% greater when incomplexed form than in non-complexed form when measured at 360 minutesof an industry-standard corneal permeability assay, and the retention ofthe complexed compound within the cornea as measured by a standardcorneal retention assay is at least 25% higher than the retention of thecompound in non-complexed form (aspect 87).

In aspects, the invention is the pharmaceutical composition of aspect87, wherein the complexing agent is a heterocyclic compound comprisingat least one five-to-seven-member nitrogenous ring comprising anattached chain of at least 3 carbons and at least one carboxylic acidgroup (aspect 88).

In aspects, the invention is the pharmaceutical composition of aspect88, wherein the complexing agent is an amino acid (aspect 89).

In aspects, the invention is the pharmaceutical composition of aspect89, wherein the complexing agent is histidine (aspect 90).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 87-90, wherein the onset of symptom improvement is atleast detectably faster than that of a similar composition comprising anon-complexed compound, as assessed by a qualified professional or asself-reported in an appropriately controlled assessment of a patientpopulation (aspect 91).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 87-91, wherein a single course of administration of atreatment comprising the composition resolves the condition for whichthe course of administration is prescribed at least 5% more frequentlythan a single course of administration of a treatment comprising asimilar composition with a non-complexed compound as measured by anappropriately controlled clinical trial (aspect 92).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 87-92, wherein the composition requires anadministration rate of no more than two-thirds of the total number ofdoses required for a similar composition comprising a non-complexedcompound over the same course of treatment (aspect 93).

In aspects, the invention is the pharmaceutical composition of aspect93, wherein the composition requires an administration rate of no morethan one half of the total number of doses required for a similarcomposition comprising a non-complexed compound over the same course oftreatment (aspect 94).

In aspects, the invention is the pharmaceutical composition of aspect94, wherein the composition requires an administration rate of no morethan one-third of the total number of doses required for a similarcomposition comprising a non-complexed compound over the same course oftreatment (aspect 95).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 87-95, wherein the rate of antibiotic resistance in apopulation receiving the composition is significantly less than in apopulation having received a similar composition comprising anon-complexed compound (aspect 96).

In aspects, the invention is the pharmaceutical composition of any oneor more of paragraphs aspects 60-67; aspects 69-79; aspects 81-89; andaspects 91-96, wherein the complexing agent is an ophthalmologicallysafe derivative of histidine having both a lipophilic and amphotericnature (aspect 97).

In aspects, the invention is the pharmaceutical composition of any oneor more of aspects 60-87 or aspects 91-97, wherein the complexing agentis an ophthalmologically safe derivative of PCL-PVAc-PEG having both alipophilic and amphoteric nature (aspect 98).

In aspects, the invention is a method of treating an ocular disease orcondition with a composition comprising a pharmaceutically activeingredient (API) comprising a compound having a structure according to:

wherein (1) R¹ is —CH—NH₂ (i.e., Me—NH₂) or an optionally substitutedalkyl, an optionally substituted aryl, an optionally substitutedaralkyl, an optionally substituted cycloalkyl, an optionally substitutedcycloalkylalkyl, an optionally substituted heterocyclyl, an optionallysubstituted heterocyclylalkyl, an optionally substituted heteroaryl, oran optionally substituted heteroarylalkyl; (2) R⁴, R⁶, R⁸, and R⁹ are—NH₂ or an optionally substituted alkyl, an optionally substituted aryl,an optionally substituted aralkyl, an optionally substituted cycloalkyl,an optionally substituted cycloalkylalkyl, an optionally substitutedheterocyclyl, an optionally substituted heterocyclylalkyl, an optionallysubstituted heteroaryl, or an optionally substituted heteroarylalkyl;(3) R² is —Me—OH or an optionally substituted alkyl, an optionallysubstituted aryl, an optionally substituted aralkyl, an optionallysubstituted cycloalkyl, an optionally substituted cycloalkylalkyl, anoptionally substituted heterocyclyl, an optionally substitutedheterocyclylalkyl, an optionally substituted heteroaryl, or anoptionally substituted heteroarylalkyl; and (4) R³, R⁵, R⁷ and R¹⁰ are—OH or an optionally substituted aryl, an optionally substitutedaralkyl, an optionally substituted cycloalkyl, an optionally substitutedcycloalkylalkyl, an optionally substituted heterocyclyl, an optionallysubstituted heterocyclylalkyl, an optionally substituted heteroaryl, oran optionally substituted heteroarylalkyl (Formula I); wherein thecompound is not tobramycin and wherein the compound is lipophilic andamphoteric in nature and further wherein the composition isophthalmologically safe detectably and wherein the presence of any ofthe R groups of (1)-(4) promotes the uptake of the composition bycorneal cells, the retention of the composition by corneal cells, orboth, as compared to tobramycin (aspect 99).

In aspects, the invention is the method of aspects 99, wherein thecompound is a derivative of tobramycin (aspect 100).

In aspects, the invention is the method of aspect 100, wherein thederivatization of tobramycin occurs by (alternatively stated, any Rgroup that differs from tobramycin is different from tobramycin by)substituting a 2-20 atom backbone alkyl or heteroalkyl group, through anester or amide bond at a position corresponding to an —OH or —NH₂ groupin tobramycin (aspect 101).

In aspects, the invention is the method of aspect 101, wherein the alkylor heteroalkyl group is a linear alkyl or heteroalkyl compound (aspect102).

In aspects, the invention is the method of aspect 102, wherein the groupgenerally consists of a fatty acid, a fatty acid derivative, a shortfatty acid, or a short fatty acid derivative (aspect 103).

In aspects, the invention is the method of aspect 103, wherein the groupgenerally consists of acetic acid, an acetic acid derivative, palmiticacid, or a palmitic acid derivative (aspect 104).

In aspects, the invention is the method of aspect 102, wherein the alkylor heteroalkyl group comprises one or more —C═O or —NH₂ derivativegroups bound to the backbone (aspect 105).

In aspects, the invention is the method of aspect 105, wherein the groupcomprises at least one —C═O group and at least one —NH₂ group bound tothe backbone (aspect 106).

In aspects, the invention is the method of aspect 102, wherein the groupcomprises no —C═O groups (aspect 107).

In aspects, the invention is the method of any one or more of aspects105-107, wherein the group comprises at least two —NH₂ groups bound tothe backbone (aspect 108).

In aspects, the invention is the method of any one or more of aspects101-108, wherein the backbone of the group is a heteroalkyl structurecomprising at least one nitrogen, at least one thiol/sulfur, or both(aspect 109).

In aspects, the invention is the method of any one or more of aspects101-109, wherein at least about 90% of the atoms of the backbone arecarbons (aspect 110).

In aspects, the invention is the method of any one or more of aspects101-110, wherein the backbone comprises or is bound to an optionallyderivatized 3-9-membered cycloalkyl or heterocycloalkyl ring (aspect111).

In aspects, the invention is the method of aspect 111, wherein thebackbone comprises or is bound to a 3-6 membered ring wherein the ringcomprises one or more nitro groups, is bound to one or more nitrogroups, or is bound to one or more side chains bound to one or morenitro groups (aspect 112).

In aspects, the invention is the method of aspect 111 or aspect 112,wherein the group comprises only one ring (aspect 113).

In aspects, the invention is the method of aspect 113, wherein thetobramycin derivative exhibits detectably faster penetration of cornealcells than tobramycin, detectably better retention in corneal cells thantobramycin, or both (aspect 114).

In aspects, the invention is the method of any one or more of aspects99-114, wherein the compound is complexed with a lipophilic andamphoteric, complexing agent (aspect 115).

In aspects, the invention is the method of aspect 115, wherein thecomplexing agent detectably increases the permeability, retention, orboth permeability and retention of the compound across and/or withincorneal cells (aspect 116).

In aspects, the invention is the method of aspect 115 or aspect 116,wherein the complexing agent is a heterocyclic compound comprising atleast one five-to-seven-member nitrogenous ring comprising an attachedchain of at least 3 carbons and at least one carboxylic acid group(aspect 117).

In aspects, the invention is the method of aspect 117, wherein thecomplexing agent is an amino acid (aspect 118).

In aspects, the invention is the method of aspect 118, wherein thecomplexing agent is histidine (aspect 119).

In aspects, the invention is the method of aspect 118, wherein thecomplexing agent is an ophthalmologically acceptable derivative ofhistidine having both a lipophilic and amphoteric nature (aspect 120).

In aspects, the invention is the method of aspect 117, wherein thecomplexing agent is a copolymer (aspect 121).

In aspects, the invention is the method of aspect 121, wherein thecomplexing agent is PCL-PVAc-PEG (aspect 122).

In aspects, the invention is the method of aspect 121, wherein thecomplexing agent is an ophthalmologically safe derivative ofPCL-PVAc-PEG having both a lipophilic and amphoteric nature (aspect123).

In aspects, the invention is the method of any one or more of aspects99-123, wherein the composition is present within a formulation, and theconcentration of the compound in the formulation is between about0.1-about 10% w/v (aspect 124).

In aspects, the invention is the method of aspect 124, wherein thecomposition is present within a formulation, and the concentration ofthe compound in the formulation is between about 0.3-about 5% w/v(aspect 125).

In aspects, the invention is the method of aspect 125, wherein thecomposition is present within a formulation, and the concentration ofthe compound in the formulation is between about 0.6-about 5% w/v(aspect 126).

In aspects, the invention is the method of aspect 126, wherein thecomposition is present within a formulation, and the concentration ofthe compound in the formulation is between about 1 and about 3% w/v(aspect 127).

In aspects, the invention is the method of aspect 127, wherein thecomposition is present within a formulation and the concentration of thecompound in the formulation approximately 2.5% w/v (aspect 128).

In aspects, the invention is the method of any one or more of aspects124-128, wherein if the formulation comprises a complexing agent, thecomplexing agent is present in the formulation in a concentrationranging from 0.1-10% w/v (aspect 129).

In aspects, the invention is the method of any one or more of aspects99-129, wherein the rate of cornea cell penetration of the compound isfaster than that of tobramycin such that the amount of compound in thecornea increases by at least about 15% or more after a period of 360minutes from administration of a similar composition comprisingtobramycin (aspect 130).

In aspects, the invention is the method of aspect 130, wherein theconcentration of compound permeating the surface of the cornea is atleast 17% greater than tobramycin when measured at 360 minutes of anindustry-standard corneal permeability assay (aspect 131).

In aspects, the invention is the method of aspect 131, wherein theconcentration of compound permeating the surface of the cornea is atleast 20% greater than tobramycin when measured at 360 minutes of anindustry-standard corneal permeability assay (aspect 132).

In aspects, the invention is the method of aspect 132, wherein theconcentration of compound permeating the surface of the cornea is atleast 25% greater than tobramycin when measured at 360 minutes of anindustry-standard corneal permeability assay (aspect 133).

In aspects, the invention is the method of aspect 133, wherein theconcentration of compound permeating the surface of the cornea is atleast 40% greater than tobramycin when measured at 360 minutes of anindustry-standard corneal permeability assay (aspect 134).

In aspects, the invention is the method of aspect 134, wherein theconcentration of compound permeating the surface of the cornea is atleast 45% greater than tobramycin when measured at 360 minutes of anindustry-standard corneal permeability assay (aspect 135).

In aspects, the invention is the method of any one or more of aspects99-135, wherein the level of retention of the compound within the corneais retained after 6 hours from administration when measured at 360minutes as measured by a standard corneal retention assay (aspect 136).

In aspects, the invention is the method of any one or more of aspects99-136, wherein the compound is retained in at least about 15% orgreater amount in corneal cells after 15 minutes than a correspondingamount of the API in TOBREX® (aspect 137).

In aspects, the invention is the method aspect 137, wherein theretention of the compound within the cornea as measured by a standardcorneal retention assay is at least 15% higher than the retention oftobramycin (aspect 138).

In aspects, the invention is the method of aspect 138, wherein theretention of the compound within the cornea is at least 17% higher thanthe retention of tobramycin when measured at 360 minutes as measured bya standard corneal retention assay (aspect 139).

In aspects, the invention is the method of aspect 139, wherein theretention of the compound within the cornea is at least 20% higher thanthe retention of tobramycin when measured at 360 minutes as measured bya standard corneal retention assay (aspect 140).

In aspects, the invention is the method of aspect 140, wherein theretention of the compound within the cornea is at least 25% higher thanthe retention of tobramycin when measured at 360 minutes as measured bya standard corneal retention assay (aspect 141).

In aspects, the invention is the method of aspect 141, wherein theretention of the compound within the cornea is at least 30% higher thanthe retention of tobramycin when measured at 360 minutes as measured bya standard corneal retention assay (aspect 142).

In aspects, the invention is the method of aspect 142, wherein theretention of the derivatized compound within the cornea is at least 32%higher than the retention of tobramycin when measured at 360 minutes asmeasured by a standard corneal retention assay (aspect 143).

In aspects, the invention is the method of any one or more of aspects99-143, wherein administration of a formulation comprising thecomposition results in the onset of symptom improvement is significantlyfaster than that of a similar composition comprising tobramycin, asassessed by a qualified professional or as self-reported in anappropriately controlled assessment of a patient population (aspect144).

In aspects, the invention is the method of any one or more of aspects99-144, wherein a single course of administration of a treatmentcomprising the composition resolves the condition for which the courseof administration is prescribed at least 5% more frequently than asingle course of administration of a treatment comprising a similarcomposition with tobramycin as measured by an appropriately controlledclinical trial (aspect 145).

In aspects, the invention is the method of any one or more of aspects99-145, wherein the administration protocol of a formulation comprisingthe composition requires an administration rate of no more thantwo-thirds of the total number of doses required for a similarcomposition comprising tobramycin over the same course of treatment(aspect 146).

In aspects, the invention is the method of aspect 146, wherein theadministration protocol of a formulation comprising the compositionrequires an administration rate of no more than one-half of the totalnumber of doses required for a similar composition comprising tobramycinover the same course of treatment (aspect 147).

In aspects, the invention is the method of aspect 147, wherein theadministration protocol of a formulation comprising the compositionrequires an administration rate of no more than one-third of the totalnumber of doses required for a similar composition comprising tobramycinover the same course of treatment (aspect 148).

In aspects, the invention is the method of any one or more of aspects99-148, wherein the rate of antibiotic resistance in a populationreceiving the composition is significantly less than the rate ofantibiotic resistance in a population having received a similarcomposition comprising tobramycin (aspect 149).

In aspects, the invention is a pharmaceutical formulation comprising anactive pharmaceutical agent according to any one or more of aspects16-49, wherein the compound is tobramycin, and wherein the formulationcomprises an effective amount of one or additional delivery agentsselected from a liposome(s), a microsphere(s), or both, which isamphoteric, lipophilic, and suitable for ophthalmologic applications,wherein the compound is retained in at least about 15% greater amount incorneal cells after 15 minutes than a corresponding amount of thecompound when no additional delivery agent is present (aspect 150).

In aspects, the invention is the pharmaceutical formulation of aspect150, wherein the presence of the one or more additional delivery agentssignificantly enhances the permeation, retention, or both permeation ofretention of the compound across and/or within corneal cells compared toa similar formulation comprising no additional delivery agents (aspect151).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 150-151, wherein the formulation further comprisesone or more excipients (aspect 152).

In aspects, the invention is the pharmaceutical formulation of aspect152, wherein the one or more excipients is selected from the groupcomprising one or more of a viscosity-enhancer, osmotic modificationagent, surfactant, chelating agent, tonicity agent, buffer, pH-adjustingagent, a preservative, or water (aspect 153).

In aspects, the invention is the pharmaceutical formulation of aspect153, wherein at least one excipient is a viscosity-enhancing excipient(aspect 154).

In aspects, the invention is the pharmaceutical formulation of aspect154, wherein the viscosity of the formulation is between about 10 cpsand about 400 cps (aspect 155).

In aspects, the invention is the pharmaceutical formulation of aspect155, wherein the formulation has a viscosity of about 25 cps to about300 cps (aspect 156).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 154-156, wherein the viscosity is at least 5% higherthan the viscosity of a similar composition which does not comprise aviscosity-enhancing agent (aspect 157).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 150-157, wherein the compound is present in theformulation in a concentration of between about 0.1-about 10% w/v(aspect 158).

In aspects, the invention is the pharmaceutical formulation of aspect158, wherein the compound is present within the formulation in aconcentration of between about 0.3-about 5% w/v (aspect 159).

In aspects, the invention is the pharmaceutical formulation of aspect159, wherein the compound is present within the formulation in aconcentration of between about 0.6-about 5% w/v (aspect 160).

In aspects, the invention is the pharmaceutical formulation of aspect160, wherein the compound is present within the formulation in aconcentration of between about 1 and about 3% w/v (aspect 161).

In aspects, the invention is the pharmaceutical formulation of aspect161, wherein the compound is present within the formulation in aconcentration of approximately 2.5% w/v (aspect 162).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 158-162, wherein the complexing agent is presentwithin the formulation in a concentration of between about 0.1-about 10%w/v (aspect 163).

In aspects, the invention is the pharmaceutical formulation of aspect163, wherein the complexing agent is present within the formulation in aconcentration of between about 0.3-5% w/v (aspect 164).

In aspects, the invention is the pharmaceutical formulation of aspect164, wherein the complexing agent is present within the formulation in aconcentration of between about 1-5% w/v (aspect 165).

In aspects, the invention is the pharmaceutical formulation of aspect165, wherein the complexing agent is present within the formulation in aconcentration of approximately 2.5% w/v (aspect 166).

In aspects, the invention is a pharmaceutical formulation comprising acomposition comprising a pharmaceutically active ingredient (API)comprising a compound having a structure according to

wherein (1) R¹ is —CH—NH₂ (i.e., Me—NH₂) or an optionally substitutedalkyl, an optionally substituted aryl, an optionally substitutedaralkyl, an optionally substituted cycloalkyl, an optionally substitutedcycloalkylalkyl, an optionally substituted heterocyclyl, an optionallysubstituted heterocyclylalkyl, an optionally substituted heteroaryl, oran optionally substituted heteroarylalkyl; (2) R⁴, R⁶, R⁸, and R⁹ are—NH₂ or an optionally substituted alkyl, an optionally substituted aryl,an optionally substituted aralkyl, an optionally substituted cycloalkyl,an optionally substituted cycloalkylalkyl, an optionally substitutedheterocyclyl, an optionally substituted heterocyclylalkyl, an optionallysubstituted heteroaryl, or an optionally substituted heteroarylalkyl;(3) R² is —Me—OH or an optionally substituted alkyl, an optionallysubstituted aryl, an optionally substituted aralkyl, an optionallysubstituted cycloalkyl, an optionally substituted cycloalkylalkyl, anoptionally substituted heterocyclyl, an optionally substitutedheterocyclylalkyl, an optionally substituted heteroaryl, or anoptionally substituted heteroarylalkyl; and (4) R³, R⁵, R⁷ and R¹⁰ are—OH or an optionally substituted aryl, an optionally substitutedaralkyl, an optionally substituted cycloalkyl, an optionally substitutedcycloalkylalkyl, an optionally substituted heterocyclyl, an optionallysubstituted heterocyclylalkyl, an optionally substituted heteroaryl, oran optionally substituted heteroarylalkyl (Formula I); wherein thecompound is not tobramycin and wherein the compound is lipophilic andamphoteric in nature and further wherein the composition isophthalmologically safe detectably and wherein the presence of any ofthe R groups of (1)-(4) promotes the uptake of the composition bycorneal cells, the retention of the composition by corneal cells, orboth, as compared to tobramycin, and further wherein the formulationcomprises an effective amount of one or additional delivery agentsselected from a liposome(s), a microsphere(s), or both, which isamphoteric, lipophilic, and suitable for ophthalmologic applications,wherein the compound is retained in at least about 15% greater amount incorneal cells after 15 minutes than a corresponding amount of thecompound when no additional delivery agent is present (aspect 167).

In aspects, the invention is the pharmaceutical formulation of aspect167, wherein the derivatization of tobramycin occurs by (alternativelystated, any R group that differs from tobramycin is different fromtobramycin by) substituting a 2-20 atom backbone alkyl or heteroalkylgroup, through an ester or amide bond at a position corresponding to an—OH or —NH₂ group in tobramycin (aspect 168).

In aspects, the invention is the pharmaceutical formulation of aspect168, wherein the alkyl or heteroalkyl group is a linear alkyl orheteroalkyl compound (aspect 169).

In aspects, the invention is the pharmaceutical formulation of aspect169, wherein the group generally consists of a fatty acid, a fatty acidderivative, a short fatty acid, or a short fatty acid derivative (aspect170).

In aspects, the invention is the pharmaceutical formulation of aspect170, wherein the group generally consists of acetic acid, an acetic acidderivative, palmitic acid, or a palmitic acid derivative (aspect 171).

In aspects, the invention is the pharmaceutical formulation of aspect171, wherein the alkyl or heteroalkyl group comprises one or more —C═Oor —NH₂ derivative groups bound to the backbone (aspect 172).

In aspects, the invention is the pharmaceutical formulation of aspect172, wherein the group comprises at least one —C═O group and at leastone —NH₂ group bound to the backbone (aspect 173).

In aspects, the invention is the pharmaceutical formulation of aspect173, wherein the group comprises no —C═O groups (aspect 174).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 172-174, wherein the group comprises at least two—NH₂ groups bound to the backbone (aspect 175).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 168-175, wherein the backbone of the group is aheteroalkyl structure comprising at least one nitrogen, at least onethiol/sulfur, or both (aspect 176).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 170-176, wherein at least about 90% of the atoms ofthe backbone are carbons (aspect 177).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 169-177, wherein the backbone comprises or is boundto an optionally derivatized 3-9-membered cycloalkyl or heterocycloalkylring (aspect 178).

In aspects, the invention is the pharmaceutical formulation of aspect178, wherein the backbone comprises or is bound to a 3-6 membered ringwherein the ring comprises one or more nitro groups, is bound to one ormore nitro groups, or is bound to one or more side chains bound to oneor more nitro groups (aspect 179).

In aspects, the invention is the pharmaceutical formulation of aspect178 or aspect 179, wherein the group comprises only one ring (aspect180).

In aspects, the invention is the pharmaceutical formulation of aspect180, wherein the tobramycin derivative exhibits detectably fasterpenetration of corneal cells than tobramycin, detectably betterretention in corneal cells than tobramycin, or both (aspect 181).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 167-181, wherein the compound is complexed with alipophilic and amphoteric, complexing agent (aspect 182).

In aspects, the invention is the pharmaceutical formulation of aspect182, wherein the complexing agent detectably increases the permeability,retention, or both permeability and retention of the compound acrossand/or within corneal cells (aspect 183).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 182-183, wherein the complexing agent is aheterocyclic compound comprising at least one five to seven membernitrogenous ring comprising an attached chain of at least 3 carbons andat least one carboxylic acid group (aspect 184).

In aspects, the invention is the pharmaceutical formulation of aspect184, wherein the complexing agent is an amino acid (aspect 185).

In aspects, the invention is the pharmaceutical formulation of aspect185, wherein the complexing agent is histidine (aspect 186).

In aspects, the invention is the pharmaceutical formulation of aspect185, wherein the complexing agent is an ophthalmologically acceptablederivative of histidine having both a lipophilic and amphoteric nature(aspect 187).

In aspects, the invention is the pharmaceutical formulation of aspect184, wherein the complexing agent is a copolymer (aspect 188).

In aspects, the invention is the pharmaceutical formulation of aspect188, wherein the complexing agent is PCL-PVAc-PEG (aspect 189).

In aspects, the invention is the pharmaceutical formulation of aspect188, wherein the complexing agent is an ophthalmologically safederivative of PCL-PVAc-PEG having both a lipophilic and amphotericnature (aspect 190).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 167-190, wherein the presence of the one or moreadditional delivery agents significantly enhances the permeation,retention, or both permeation of retention of the compound across and/orwithin corneal cells compared to a similar formulation comprising noadditional delivery agents (aspect 191).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 167-191, wherein the formulation further comprisesone or more excipients (aspect 192).

In aspects, the invention is the pharmaceutical formulation of aspect192, wherein the one or more excipients is selected from the groupcomprising one or more of a viscosity-enhancer, osmotic modificationagent, surfactant, chelating agent, tonicity agent, buffer, pH-adjustingagent, a preservative, or water (aspect 193).

In aspects, the invention is the pharmaceutical formulation of aspect193, wherein at least one excipient is a viscosity-enhancing excipient(aspect 194).

In aspects, the invention is the pharmaceutical formulation of aspect194, wherein the viscosity of the formulation is between about 10 cpsand about 400 cps (aspect 195).

In aspects, the invention is the pharmaceutical formulation of aspect195, wherein the formulation has a viscosity of about 25 cps to about300 cps (aspect 196).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 194-196, wherein the viscosity is at least 5% higherthan the viscosity of a similar composition comprising the compoundwithout the viscosity-enhancing agent (aspect 197).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 167-197, wherein the compound is present in theformulation in a concentration of between about 0.1-about 10% w/v(aspect 198).

The pharmaceutical formulation of aspect 198, wherein the compound ispresent within the formulation in a concentration of between about0.3-about 5% w/v (aspect 199).

In aspects, the invention is the pharmaceutical formulation of aspect199, wherein the compound is present within the formulation in aconcentration of between about 0.6-about 5% w/v (aspect 200).

In aspects, the invention is the pharmaceutical formulation of aspect200, wherein the compound is present within the formulation in aconcentration of between about 1 and about 3% w/v (aspect 201).

In aspects, the invention is the pharmaceutical formulation of aspect201, wherein the compound is present within the formulation in aconcentration of approximately 2.5% w/v (aspect 202).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 198-202, wherein the complexing agent, when present,is present in the formulation in a concentration of between about0.1-10% w/v (aspect 203).

In aspects, the invention is a pharmaceutical formulation comprising anantimicrobial active pharmaceutical ingredient (API) comprising aneffective amount of a compound having a structure according to Formula Iwherein (1) R¹ is —CH—NH₂ (i.e., Me—NH₂) or an optionally substitutedalkyl, an optionally substituted aryl, an optionally substitutedaralkyl, an optionally substituted cycloalkyl, an optionally substitutedcycloalkylalkyl, an optionally substituted heterocyclyl, an optionallysubstituted heterocyclylalkyl, an optionally substituted heteroaryl, oran optionally substituted heteroarylalkyl; (2) R⁴, R⁶, R⁸, and R⁹ are—NH₂ or an optionally substituted alkyl, an optionally substituted aryl,an optionally substituted aralkyl, an optionally substituted cycloalkyl,an optionally substituted cycloalkylalkyl, an optionally substitutedheterocyclyl, an optionally substituted heterocyclylalkyl, an optionallysubstituted heteroaryl, or an optionally substituted heteroarylalkyl;(3) R² is —Me—OH or an optionally substituted alkyl, an optionallysubstituted aryl, an optionally substituted aralkyl, an optionallysubstituted cycloalkyl, an optionally substituted cycloalkylalkyl, anoptionally substituted heterocyclyl, an optionally substitutedheterocyclylalkyl, an optionally substituted heteroaryl, or anoptionally substituted heteroarylalkyl; and (4) R³, R⁵, R⁷ and R¹⁰ are—OH or an optionally substituted aryl, an optionally substitutedaralkyl, an optionally substituted cycloalkyl, an optionally substitutedcycloalkylalkyl, an optionally substituted heterocyclyl, an optionallysubstituted heterocyclylalkyl, an optionally substituted heteroaryl, oran optionally substituted heteroarylalkyl, and an effective amount of aliposome or microsphere delivery agent, which is amphoteric, lipophilic,and suitable for ophthalmologic applications, wherein the compound isretained in at least about 15% greater amount in corneal cells after 15minutes than a corresponding amount of the compound when not presentwith the liposome or microsphere delivery agent (aspect 204).

In aspects, the invention is the pharmaceutical formulation of aspect204, wherein the compound is not tobramycin (aspect 205).

In aspects, the invention is the pharmaceutical formulation of aspect204, wherein the compound is tobramycin (aspect 206).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 204-206, wherein the compound is complexed with acomplexing agent comprising a heterocyclic compound comprising at leastone five-to-seven-member nitrogenous ring comprising an attached chainof at least 3 carbons and at least one carboxylic acid group (aspect207).

In aspects, the invention is the pharmaceutical formulation of aspect207, wherein the complexing agent is an amino acid (aspect 208).

In aspects, the invention is the pharmaceutical formulation of aspect208, wherein the complexing agent is histidine (aspect 209).

In aspects, the invention is the pharmaceutical formulation of aspect208, wherein the complexing agent is an ophthalmologically acceptablederivative of histidine having both a lipophilic and amphoteric nature(aspect 210).

In aspects, the invention is the pharmaceutical formulation of aspect207, wherein the complexing agent is a copolymer (aspect 211).

In aspects, the invention is the pharmaceutical formulation of aspect211, wherein the complexing agent is PCL-PVAc-PEG (aspect 212).

In aspects, the invention is the pharmaceutical formulation of aspect211, wherein the complexing agent is an ophthalmologically safederivative of PCL-PVAc-PEG having both a lipophilic and amphotericnature (aspect 213).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 207-213, wherein the presence of the complexing agentsignificantly enhances the permeation, retention, or both permeation ofretention of the compound across, within, or both across and/or withincorneal cells compared to a similar formulation comprising no complexingagent (aspect 214).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 202-214, wherein the formulation further comprisesone or more excipients (aspect 215).

In aspects, the invention is the pharmaceutical formulation of aspect215, wherein the one or more excipients is selected from the groupcomprising one or more of a viscosity-enhancer, osmotic modificationagent, surfactant, chelating agent, tonicity agent, buffer, pH-adjustingagent, a preservative, or water (aspect 216).

In aspects, the invention is the pharmaceutical formulation of aspect216, wherein at least one excipient is a viscosity-enhancing excipient(aspect 217).

In aspects, the invention is the pharmaceutical formulation of aspect217, wherein the viscosity of the formulation is between about 10 cpsand about 400 cps (aspect 218).

In aspects, the invention is the pharmaceutical formulation of aspect218, wherein the formulation has a viscosity of about 25 cps to about300 cps (aspect 219).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 217-219, wherein the viscosity is at least 5% higherthan the viscosity of a similar composition comprising noviscosity-enhancing agent (aspect 220).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 204-220, wherein the compound is present in theformulation in a concentration of between about 0.1-about 10% w/v(aspect 221).

In aspects, the invention is the pharmaceutical formulation of aspect221, wherein the compound is present within the formulation in aconcentration of between about 0.3-about 5% w/v (aspect 222).

In aspects, the invention is the pharmaceutical formulation of aspect222, wherein the compound is present within the formulation in aconcentration of between about 0.6-about 5% w/v (aspect 223).

In aspects, the invention is the pharmaceutical formulation of aspect223, wherein the compound is present within the formulation in aconcentration of between about 1 and about 3% w/v (aspect 224).

In aspects, the invention is the pharmaceutical formulation of aspect224, wherein the compound is present within the formulation in aconcentration of approximately 2.5% w/v (aspect 225).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 221-225, wherein the complexing agent, when present,is present in the formulation in a concentration of between about0.1-10% w/v (aspect 226).

In aspects, the invention is the pharmaceutical formulation according toany one or more of aspects 150-226, wherein the compound is retained inat least about a 15% greater amount in corneal cells after 15 minutesthan the API in TOBREX® as measured by a standard corneal cell retentionassay (aspect 227).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 150-227, wherein the formulation is delivered as asolution, emulsion, dispersion, or suspension (aspect 228).

In aspects, the invention is the pharmaceutical formulation of aspect228, wherein the formulation is delivered as a solution (aspect 229).

In aspects, the invention is the pharmaceutical formulation of aspect229, wherein the formulation is administered via drops to the eye(aspect 230).

In aspects, the invention is the pharmaceutical formulation of aspect228, wherein the formulation is delivered as an ointment (aspect 231).

In aspects, the invention is the pharmaceutical formulation of aspect231, wherein the formulation is administered by applying a strip of theointment to the eye (aspect 232).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 150-232, wherein the formulation maintains thecompound in contact with the ocular surface (mucous membrane) of the eyefor at least 2 hours after application (aspect 233).

In aspects, the invention is the pharmaceutical formulation of aspect233, wherein the formulation maintains the active in contact with theocular surface (mucous membrane) of the eye after applying for at leastapproximately 4 hours after application (aspect 234).

In aspects, the invention is the pharmaceutical formulation of aspect234, wherein the formulation maintains the active in contact with theocular surface (mucous membrane) of the eye after applying for at leastapproximately 8 hours after application (aspect 235).

In aspects, the invention is the pharmaceutical formulation of aspect235, wherein the formulation maintains the active in contact with theocular surface (mucous membrane) of the eye after applying for at leastapproximately 16 hours after application (aspect 236).

In aspects, the invention is the pharmaceutical formulation of aspect236, wherein the formulation maintains the active in contact with theocular surface (mucous membrane) of the eye after applying for at leastapproximately 20 hours after application (aspect 237).

In aspects, the invention is the pharmaceutical formulation of aspect237, wherein the formulation maintains the active in contact with theocular surface (mucous membrane) of the eye after applying for at leastapproximately 24 hours after application (aspect 238).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 150-238, wherein the formulations demonstrate atleast 5% higher patient compliance as compared to TOBREX® as assessed byone or more physicians in an appropriately powered population ofpatients, by self-reported patient survey in an appropriately poweredstudy, or by an appropriately powered clinical study (aspect 239).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 150-239, wherein the formulations demonstrate atleast 5% better efficacy as compared to TOBREX® as assessed by one ormore physicians in an appropriately powered population of patients or byan appropriately powered clinical study (aspect 240).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 150-240, wherein the formulations demonstrate atleast 5% less surface toxicity as compared to TOBREX® as assessed by oneor more physicians in an appropriately powered population of patients orby an appropriately powered clinical study (aspect 241).

In aspects, the invention is the pharmaceutical formulation of any oneor more of aspects 150-241, wherein the formulations demonstrate that onaverage fewer than 2 people in 100 treated with the formulationexperience a hypersensitivity or localized ocular toxicity reaction suchas lid itching and swelling, and conjunctival erythema as assessed byone or more physicians in an appropriately powered population ofpatients or by an appropriately powered clinical study (aspect 242).

In aspects, the invention is the pharmaceutical formulation of any ormore of aspects 150-242, wherein the formulation further comprises oneor more additional actives (aspect 243).

In aspects, the invention is the pharmaceutical formulation of aspect243, wherein the active is an anti-inflammatory (aspect 244).

In aspects, the invention is the pharmaceutical formulation of aspect243, wherein the active is a steroid (aspect 245).

In aspects, the invention is the pharmaceutical formulation of aspect245, wherein the active is dexamethasone (aspect 246).

In aspects, the invention is a method of reducing the level of bacterialinfection present in an eye comprising application of a formulationaccording to any one or more of aspects 150-246 (aspect 247).

In aspects, the invention is a method of using a formulation accordingto any one or more of aspects 150-247 to treat a patient suffering froman ocular disease or condition which may be sensitive to such aformulation (aspect 248).

In aspects, the invention is the method of aspect 248, wherein thedisease or condition is an external infection of the eye (aspect 249).

In aspects, the invention is the method of aspect 249, wherein theexternal infection is caused by a pathogen selected from a groupcomprising a gram-positive or a gram-negative ophthalmic pathogen(aspect 250).

In aspects, the invention is the method of aspect 250, wherein thepathogen is a Staphylococci, such as S. Aureus and S. epidermis (aspect251).

In aspects, the invention is the method of any one or more of aspects250-251, wherein the pathogen is a penicillin-resistant strain (aspect252).

In aspects, the invention is the method of any one or more of aspects247-252, wherein the concentration of the compound is between about0.1-about 10% w/v (aspect 253).

In aspects, the invention is the method of aspect 253, wherein theconcentration of the compound is between about 0.3-5% w/v (aspect 254).

In aspects, the invention is the method of aspect 254, wherein theconcentration of the compound is between about 0.6-5% w/v (aspect 255).

In aspects, the invention is the method of aspect 255, wherein theconcentration of the compound is between about 1-3% w/v (aspect 256).

In aspects, the invention is the method of aspect 256, wherein theconcentration of the compound is approximately 2.5% w/v (aspect 257).

In aspects, the invention is the method of any one or more of aspects253-257, wherein the concentration of the complexing agent, when presentin the formulation, is present in a concentration of between about0.1-10% w/v (aspect 258).

In aspects, the invention is the method of aspect 258, wherein theconcentration of the complexing agent, when present in the formulation,is present in a concentration of between about 0.3-5% w/v (aspect 259).

In aspects, the invention is the method of aspect 259, wherein theconcentration of the complexing agent, when present in the formulation,is present in a concentration of between about 0.6-5% w/v (aspect 260).

In aspects, the invention is the method of aspect 260, wherein theconcentration of the complexing agent, when present in the formulation,is present in a concentration of between about 1-3% w/v (aspect 261).

In aspects, the invention is the method of aspect 261, wherein theconcentration of the complexing agent, when present in the formulation,is present in a concentration of approximately 2.5% w/v (aspect 262).

In aspects, the invention is the method of any one or more of aspects247-262, wherein the formulation is administered four times per day orless (aspect 263).

In aspects, the invention is the method of aspect 263, wherein theformulation is administered three times per day or less (aspect 264).

In aspects, the invention is the method of aspect 264, wherein theformulation is administered twice per day or less (aspect 265).

In aspects, the invention is the method of aspect 265, wherein theformulation is administered once daily (aspect 266).

The invention claimed is:
 1. A pharmaceutical formulation comprising:(1) an ophthalmologically suitable complex, the complex comprising (a)tobramycin or a derivative thereof; and (b) histidine, which forms acomplex with the tobramycin or a derivative thereof, (2) apharmaceutically effective amount of dexamethasone or a pharmaceuticallyacceptable derivative thereof, wherein the histidine detectably promotesthe uptake of the tobramycin or derivative thereof by corneal cells, theretention of the tobramycin or derivative thereof by corneal cells, orboth, as compared to the free (non-complexed) tobramycin or derivativethereof.
 2. The pharmaceutical composition of claim 1, wherein thedexamethasone or the pharmaceutically suitable derivative thereof ispresent in a concentration of about 0.02-about 0.15% w/v.
 3. Thepharmaceutical composition of claim 2, wherein the dexamethasone or thepharmaceutically suitable derivative thereof is dexamethasone.
 4. Thepharmaceutical composition of claim 3, wherein the complex is present inan amount of about 0.3-about 5% w/v.
 5. The pharmaceutical compositionof claim 1, wherein the complex is present in an amount of about0.3-about 5% w/v.
 6. The pharmaceutical composition of claim 1, whereinthe concentration of compound permeating the surface of the cornea is atleast about 15% greater after 15 minutes from application than acorresponding amount of tobramycin in a composition consisting oftobramycin at 0.3% w/v, benzalkonium chloride at 0.01% w/v, boric acidat 1.24% w/v, sodium sulfate at 0.152% w/v, sodium chloride at 0.278%w/v, tyloxapol at 0.1% w/v, sodium hydroxide and/or sulfuric acid, andpurified water.
 7. The pharmaceutical composition of claim 2, wherein aneffective amount of the composition prevents detectable or significantgrowth of a bacterial infective agent for a period of at least 6 hoursafter administration.
 8. The pharmaceutical composition of claim 1,wherein an effective amount of the composition prevents detectable orsignificant growth of a bacterial infective agent for a period of atleast 6 hours after administration.
 9. The pharmaceutical composition ofclaim 4, wherein an effective amount of the composition preventsdetectable or significant growth of a bacterial infective agent for aperiod of at least 6 hours after administration.
 10. The pharmaceuticalcomposition of claim 1, wherein the histidine and the tobramycin orderivative thereof are present in a weight/weight ratio of about 0.5:1to about 2:1.